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THE OBSERVER’S HANDBOOK 1966

Fifty-eighth Year of Publication THE ROYAL ASTRONOMICAL SOCIETY OF CANADA

Price One Dollar T ROYAL ASTRONOMICAL SOCIETY OF CANADA

Incorporated 1890 — Royal Charter 1903

The National Office of the Royal Astronomical Society of Canada is located at 252 College Street, Toronto 2B, Ontario. The business office of the Society, reading rooms and astronomical library, are housed here, as well as a large room for the accommodation of telescope making groups. Membership in the Society is open to anyone interested in . Applicants may affiliate with one of the Society’s sixteen centres across Canada, or may join the National Society directly. Centres of the Society are established in Halifax, Quebec, Montreal, Ottawa, Kingston, Hamilton, Niagara Falls, London, Windsor, Winnipeg, Edmonton, Calgary, Vancouver, Victoria, and Toronto. Addresses of the Centres’ secretaries may be obtained from the National Office. Publications of the Society are free to members, and include the J o u r n a l (6 issues per year) and the Observer’s Handbook (published annually in November). Annual fees of S7.50 are payable October 1 and include the publi­ cations for the following year. Requests for additional information regarding the Society or its publications may be sent to 252 College Street, Toronto 2B, Ontario.

VISITING HOURS AT SOME CANADIAN OBSERVATORIES David Dunlap Observatory, Richmond Hill, Ont. Wednesday afternoons, 2:00-3:00 p.m. Saturday evenings, April through October (by reservation). Dominion Astrophysical Observatory, Victoria, B.C. Monday to Friday, daytime, no programme. Saturday evenings, April through November. Dominion Observatory, Ottawa, Ont. Monday to Friday, daytime, rotunda only. Saturday evenings, April through October. Dominion Radio Astrophysical Observatory, Penticton, B.C. Sunday, July and August only (2:00-5:00 p.m.)

Planetariums: McMaster University, Hamilton, Ont. (group reservations only). Nova Scotia Museum, Halifax, Tuesday only, 8:00 p.m. Queen Elizabeth , Edmonton, Alta., Monday-Wednesday, 7:30 p.m. (closed Thursday), Friday, 7:30 p.m., Saturday, 3:30 p.m., Sunday, 2:00-4:00 p.m. THE OBSERVER’S HANDBOOK 1966

E d it o r

R u t h J . N o r t h c o t t

Fifty-eighth Year of Publication THE ROYAL ASTRONOMICAL SOCIETY OF CANADA

252 College Street, Toronto 2B, O n t a r i o CONTENTS

PAGE Acknowledgements...... 3 Anniversaries and Festivals; Julian Day Calendar...... 3 Symbols and A bbreviations ...... 4 The Constellations...... 5 Ephemeris of the and Correction to S u n -d ia l...... 7 Principal Elements of the ...... 8 Satellites of the Solar S y stem ...... 9 Solar, Sidereal and Ephemeris T im e ...... 10 Map of Standard Time Zones; Radio Time Signals...... 11 Times of Rising and Setting of the Sun and M o on...... 12 Sunrise and S u n s e t ...... 13 Beginning and Ending of T w ilig h t...... 19 Moonrise and M o o n s e t...... 20 The Sun and P lan ets ...... 26 The Sky and Astronomical Phenomena Month by M o n th ...... 32 Phenomena of ’s Satellites...... 56 ’s Satellites ...... 57 Jupiter’s Belts and Zones; Dimensions of Saturn’s R in g s ...... 59 Longitudes of Jupiter’s Central M e rid ian ...... 60 The Polar A urora ...... 61 The Observation of the M oon...... 61 Ephemeris for the Physical Observation of the Sun...... 63 ; Lunar O ccultation s...... 64 Planetary Appulses and ...... 69 Ephemerides of the Brightest ...... 69 Meteors, Fireballs and Meteorites...... 71 Table of Precession for 50 Y e a r s ...... 72 Finding List of Named S ta rs ...... 73 The Brightest , their magnitudes, types, proper motions, distances and radial velocities and navigation s t a r s ...... 74 Double and Multiple Stars...... 85 The Nearest S ta rs ...... 86 Variable S ta rs ...... 88 Cluster and Nebulae C lusters ...... 90 Galactic N ebulae ...... 91 External ...... 92 Radio Sources ...... 93 Four Circular Star M a p s ...... 94

PRINTED IN CANADA BY THE UNIVERSITY OF TORONTO PRESS THE OBSERVER’S HANDBOOK for 1966 is the 58th edition. Some changes in the data include the epoch for star positions from 1960 to 1970, the times of sunrise and sunset, and of twilight, for the current year instead of average values, and the table of the Central Meridian of has been replaced by an illustration of the standard Auroral forms. Cordial thanks are offered to all individuals who assisted in the preparation of this edition, to those whose names appear in the various sections and to John Booker, Peter Broughton, Barbara Gaizauskas, Helen Sawyer Hogg, Joan Reick Hube, John Scherk, Bill Sherwood, Maude Towne, Isabel Williamson and Dorothy Yane. Special thanks are extended to Margaret W. Mayall, Director of the A.A.V.S.O., for the predictions of Algol and the variable stars and to Gordon E. Taylor and the British Astronomical Association for the prediction of planetary appulses and occultations. My deep indebtedness to the British Nautical Almanac Office and to the American Ephemeris is gratefully acknowledged. R u t h J. N o r t h c o t t

ANNIVERSARIES AND FESTIVALS, 1966 New Year’s D ay...... Sat. Jan. 1 Pentecost (Whit Sunday) . . . . May 29 Epiphany...... Thu. Jan. 6 Trinity Sunday...... June 5 Accession of Queen Corpus Christi...... Thu. June 9 Elizabeth (1952). . . . Sun. Feb. 6 St. John Baptist (Mid­ Septuagesima Sunday. Feb. 6 summer Day)...... Fri. June 24 Quinquagesima (Shrove Dominion D ay...... Fri. July 1 Sunday)...... Feb. 20 Birthday of Queen Mother Ash Wednesday...... Feb. 23 Elizabeth (1900). . . .Thu. Aug. 4 St. David...... Tue. Mar. 1 Labour Day...... Mon. Sept. 5 St. Patrick...... Thu. Mar. 17 Hebrew New Year Palm Sunday...... Apr. 3 (Rosh Hashanah)... .Thu. Sept. 15 Good Friday...... 8 St. Michael (Michael­ Easter Sunday...... Apr. 10 mas D ay)...... Thu. Sept. 29 Birthday of Queen Thanksgiving...... Mon. Oct. 10 Elizabeth (1926). . . .Thu. Apr. 21All Saints’ D ay...... Tue. Nov. 1 St. George...... Sat. Apr. 23 Remembrance Day. . . .Fri. Nov. 11 Rogation Sunday...... May 15 First Sunday in Advent...... Nov. 27 Ascension D ay...... Thu. May 19 St. Andrew...... Wed. Nov. 30 Victoria Day...... Mon. May 23 Christmas Day...... Sun. Dec. 25

JULIAN DAY CALENDAR, 1966 J.D. 2,430,000 plus the following: Jan. 1 ...... 9,127 May 1 9,247 Sept. 1. . . . 9,370 Feb. 1 ...... 9,158 June 1 9,278 Oct. 1. . . . 9,400 Mar. 1 ...... 9,186 July 1 9,308 Nov. 1. . . . 9,431 Apr. 1 ...... 9,217 Aug. 1 9,339 Dec. 1. . . . 9,461 The Julian Day commences at noon. Thus J.D. 2,439,127.0 = Jan. 1.5 U.T. SUN, AND The Sun The Moon generally Jupiter Mercury Saturn Full Moon Uranus First Quarter Last Quarter

ASPECTS AND ABBREVIATIONS Conjunction, or having the same Longitude or . Opposition, or differing 180° in Longitude or Right Ascension. Quadrature, or differing 90° in Longitude or Right Ascension. Ascending Node; Descending Node. a or R.A., Right Ascension; δ or Dec., , h, m, s, Hours, Minutes, Seconds of Time. ° ' ", Degrees, Minutes, Seconds of Arc.

SIGNS OF THE ZODIAC Aries...... 0° Leo...... 120° Sagittarius . . .240° Taurus...... 30° Virgo...... 150° Capricornus . . 270° ...... 60° Libra...... 180° Aquarius...... 300° ...... 90° Scorpius...... 210° Pisces...... 330°

THE GREEK ALPHABET Alpha Iota Rho Beta Kappa Sigma Gamma Lambda Tau Delta Mu Upsilon Epsilon Nu Phi Zeta Xi Chi Eta Omicron Psi Theta Pi Omega

THE CONFIGURATIONS OF JUPITER’S SATELLITES In the Configurations of Jupiter’s Satellites (pages 33, 35, etc.), O represents the disk of the , d signifies that the satellite is on the disk, * signifies that the satellite is behind the disk or in the shadow. Configurations are for an inverting telescope.

CALCULATIONS FOR ALGOL The calculations for the minima of Algol are based on the epoch J.D. 2437965.6985 and period 2.8673285 days as published in Sky and Telescope, 1963.

CELESTIAL DISTANCES Celestial distances given herein are based on the standard value of 8.80" for the sun’s parallax, and the astronomical unit of 92.9 million miles. L a t in a n d F r e n c h N a m e s w it h A bbreviations The approximate position of the centre of each constellation is indicated by the right ascension in hours and the declination as follows: on the zodiac, Z; on the equator, E; northern hemisphere, N; southern hemisphere, S; italics are used for constellations completely within 45° of a pole.

Andromeda, Andromede...... And 1 N Indus, In d ien (l'Oiseau) ...... Ind 21 S Antlia, La Machine Pneumatique.A nt 10 S Lacerta, Le Lezard...... Lac 22 N Apus, L ’Oiseau de Paradis...... Aps 16 S Leo, Le L io n ...... Leo 10 Z Aquarius, Le Verseau...... Aqr 22 Z Leo Minor, Le Petit Lion ...... LM i 10 N Aquila, L 'A igle...... Aql 19 E Lepus, Le L ievre...... Lep 5 S Ara, L ’A utel...... Ara 17S Libra, La Balance...... Lib 15 Z Aries, Le Belier...... Ari 2 Z Lupus, Le Loup...... Lup 15 s Auriga, Le Cocker...... Aur 5 N Lynx, Le L y n x ...... Lyn 7 N Bootes, Le Bouvier...... Boo 14 N Lyra, La Lyre...... Lyr 18 N Caelum, Le Burin du Graveur. . . . Cae 4 S Mensa, La Table...... M en 5 S Camelopardalis, La Girafe...... Cam 6 N Microscopium, Le Microscope. . . . Mic 20 S Cancer, Le Cancer...... Cnc 8 Z Monoceros, La Licorne...... Mon 6 E Canes Venatici, Musca, La Mouche...... Mus 12 S Les Chiens de Chasse...... CVn 13 N Norma, La Regie...... N or 15 S Canis Major, Le Grand Chien... .CMa 6 S Octans, L'Octant...... Oct — S Canis Minor, Le Petit Chien...... CMi 7 N Ophiuchus, Ophiuchus...... Oph 17 E Capricornus, Le Capricorne...... Cap 21 Z O rion, Orion...... Ori 5 E Carina, La Carene du Navire. . . .C ar 8S Pavo, Le P aon...... Pav 19 S Cassiopeia, Cassiopee...... Cas 1 N Pegasus, Pegase...... Peg 22 N C entaurus, Le Centaure...... Cen 12 S Perseus, Persee...... Per 3 N Cepheus, Cephee...... Cep 23 N Phoenix, Le P henix...... Phe 0 S C etus, La Baleine...... Cet 1 E Pictor, Peintre (le Chevalet d u ).. .Pic 5 s Chamaeleon, Le Camel eon...... Cha 10 S Pisces, Les Poissons...... Psc 0 Z Circinus, Le Compas...... Cir 14 S Piscis Austrinus, Columba, La Colombe...... Col 5 S Le Poisson Austral...... PsA 22 s Coma Berenices, La Chevelure Puppis, La Poupe du Navire.. .. .Pup 7 s de Berenice...... Com 12 N Pyxis, La Boussole...... Pyx 8 s Corona Australis, Reticulum, Le Reticule...... Ret 3 S La Couronne Australe...... CrA 18 S Sagitta, La Fleche...... Sge 19 N Corona Borealis, Sagittarius, Le Sagittaire...... Sgr 18 Z La Couronne Boreale...... CrB 15 N Scorpius, Le Scorpion...... Sco 16 Z Corvus, Le Corbeau...... Crv 12 S Sculptor, Sculpteur (VAtelier du).Scl 0 s C rater, La Coupe...... Crt 11 S Scutum, L 'E c u ...... Sct 18 s Crux, La Croix du Sud ...... Cru 12 S Serpens, Le Serpent...... Ser 16 E Cygnus, Le Cygne...... Cyg 20 N Sextans, Le Sextant...... Sex 10 E Delphinus, Le D auphin...... Del 20 N Taurus, Le Taureau...... Tau 4 Z Dorado, La Dorade...... Dor 5 S Telescopium, Le Telescope...... Tel 19 S Draco, Le Dragon...... D ra 16 N Triangulum, Le Triangle...... Tri 2 N Equuleus, Le Petit Cheval...... Equ 21 N Triangulum Australe, Eridanus, E ridan...... Eri 3 S Le Triangle Austral...... TrA 16 5 Fornax, Le Fourneau...... For 2 S Tucana, Le Toucan...... Tuc 23 S Gemini, Les Gtmeaux...... Gem 7 Z Ursa Major, La Grande Ourse... .U M a 11 N Grus, La Grue...... Gru 22 S Ursa Minor, La Petite Ourse.... UM i — N Hercules, Hercule...... Her 17 N Vela, Les Voiles du Navire...... Vel 9 S Horologium, L'Horloge...... Hor 3 S Virgo, La Vierge...... Vir 13 Z H ydra, L ’Hydre Femelle...... H ya 11 S Volans, Le Poisson Volant...... Vol 7 S H ydrus, L'Hydre Male...... Hyi 2 S Vulpecula, Le Renard...... Vul 20 N MISCELLANEOUS ASTRONOMICAL DATA

U n i t s o f L e n g t h 1 Angstrom unit = 10-8 cm. 1 micron, µ = 10-4cm .= 104A. 1 inch = exactly 2.54 centimetres 1 cm. = 0.39370. . . in. 1 yard = exactly 0.9144 metre 1 m. = 102 cm. = 1.0936. . . yb. 1 mile = exactly 1.609344 kilometres 1 km. = 105 cm. = 0.62137. . . mi. 1 astronomical unit = 1.495X1013 cm. = 1.495X108 km. = 9.29X107 mi. 1 light-year = 9.460X1017 cm. = 5.88 X1012 mi. = 0.3068 parsecs 1 parsec = 3.084 X1018 cm. = 1.916 X1013 mi. = 3.260 l.y. 1 megaparsec = 106 parsecs

U n i t s o f T im e Sidereal day = 23h 56m 04.095 of mean solar time Mean solar day = 24h 03m 56.565 of mean sidereal tim e Synodic month = 29d 12h 44m 03s Sidereal month = 27d 07h 43m 12s Tropical year (ordinary) = 365d 05h 48m 46s Sidereal year = 365d 06h 09m 10s year = 346d 14h 52m 52s

T h e E a r t h Equatorial radius, a = 6378.39 km. = 3963.35 mi.; flattening, c = (a — b)/a = 1/297 Polar radius, b = 6356.91 km. = 3950.01 mi. 1° of latitude = 111.137 — 0.562 cos 2φ km. = 69.057 — 0.349 cos 2φ mi. (at lat.φ) 1° of longitude = 111.418 cosφ — 0.094 cos 3φ km. = 69.232 cosφ —0.0584 cos 3φ mi. Mass of earth = 5.98 X1024 kgm. = 13.2 X1024 lb. Velocity of escape from © = 11.2 km./sec. = 6.94 mi./sec.

E a r t h ’s O r b i t a l M o t io n Solar parallax = 8".80 (adopted); recent determination = 8".794 (radar, , 1962) Constant of aberration = 20".47 (adopted) Annual general precession = 50".26; obliquity of = 23° 26' 40" (1960) Orbital velocity = 29.8 km./sec. = 18.5 mi./sec. Parabolic velocity at © = 42.3 km./sec. = 26.2 mi./sec.

S o l a r M o t io n Solar apex, R.A. 18h 04m, Dec. + 30°; solar velocity = 19.4 km ./sec. = 12.1 mi./sec.

T h e G a l a c t ic S y s t e m North pole of galactic plane R.A. 12h 49m, Dec. + 27.°4 (1950) Centre of R.A. 17h 42.4m, Dec. — 28° 55' (1950) (zero pt. for new gal. coord.) Distance to centre ~ 10,000 parsecs; diameter ~ 30,000 parsecs Rotational velocity (at sun) ~ 262 km./sec. Rotational period (at sun) ~ 2.2 X108 years Mass ~ 2X1011 solar masses

E x t e r n a l G a l a x i e s Red Shift ~ + 100 km./sec./megaparsec ~ 19 milee/sec./million l.y.

R a d i a t i o n C o n s t a n t s Velocity of light, c = 299,860 km./sec. = 186,324 mi./sec. (adopted); recent value, 299,792.50± 0.10 km./sec. (Froome, Nature, 1958) Solar constant = 1.93 gram calories/square cm./minute Light ratio for one magnitude = 2.512 . . . ; log ratio = exactly 0.4 Stefan’s constant = 5.6694 X10- 5 c.g.s. units

M iscellaneous Constant of gravitation, G = 6.670X10-8 c.g.s. units Mass of the electron, m = 9.1083 X10-28 gm.; mass of the proton = 1.6724X10-24 gm Planck’s constant, h = 6.625 X10-27 erg. sec. Loschmidt’s number = 2.6872 X1019 molecules/cu. cm. of gas at S.T.P. Absolute temperature = T° K = T° C+273° = 5/9 (T° F+ 459°) 1 radian = 57°.2958 π = 3.141,592,653,6 = 3437'.75 No. of square degrees in the sky = 41,253 = 206,265" 1 gram = 0.03527 oz. 1966 EPHEMERIS OF THE SUN AND CORRECTION TO SUN-DIAL PRINCIPAL ELEMENTS OF THE SOLAR SYSTEM MEAN ORBITAL ELEMENTS (for epoch 1960 Jan. 1.5 E.T.)

Mean Distance Period of Long. Mean from Sun Revolution Eccen­ In­ Long. of Long. Planet (a) tri­ clina­ of Peri­ at millions Sidereal Syn­ city tion Node helion Epoch A. U. of miles (P) odic (e) (i) ( ) (π) (L) ° ° ° days Mercury 0.387 36.0 88.0d. 116 .206 76.8 Venus 0.723 67.2 224.7 584 .007 3.4 76.3 131.0 174.3 Earth 1.000 92.9 365.26 .017 0.0 0.0 102.3 100.2 Mars 1.524 141.5 687.0 780 .093 1.8 49.2 335.3 258.8 Jupiter 5.203 483.4 11.86y. 399 .048 1.3 100.0 13.7 259.8 Saturn 9.539 886. 29.46 378 .056 2.5 113.3 92.3 280.7 Uranus 19.18 1782. 84.01 370 .047 0.8 73.8 170.0 141.3 Neptune 30.06 2792. 164.8 367 .009 1.8 131.3 44.3 216.9 Pluto 39.44 3664. 247.7 367 .250 17.2 109.9 224.2 181.6

PHYSICAL ELEMENTS

Equa­ Mean Sur­ Inclina­ torial Den­ face tion of Di­ Ob­ Mass sity Grav­ 7.0Rotation47.9 Equator Albedo*222.6 Object ameter late­ ity Period to Orbit ness water miles = 1 = 1 = 1 °

O Sun 864,000 0 333,000 1.41 27.9 25d-35d+ ++ Moon 2,160 0 0.0123 3.34 0.16 27d 07h 43m 6.7 0.067 Mercury 3,100 0 0.056 5.13 0.36 59d § ? 0.056 9 Venus 7,700 0 0.817 4.97 0.87 225d++ 32 0.76 © Earth 7,927 1/297 1.000 5.52 1.00 23h 56m 04s 23.4 0.36 Mars 4,200 1/192 0.108 3.94 0.38 24 37 23 24.0 0.16 Jupiter 88,700 1/16 318.0 1.33 2.64 9 50 30 3.1 0.73 Saturn 75,100 1/10 95.2 0.69 1.13 10 14 26.7 0.76 Uranus 29,200 1/16 14.6 1.56 1.07 10 49 97.9 0.93 Neptune 27,700 1/50 17.3 2.27 1.41 14 ? 28.8 0.84 Pluto 8,700? ? 0.9? 4? ? 6.39d ? ? 0.14

Source of data is “Explanatory Supplement to the Ephemeris”, 1961, except those marked * which are from D. C. Harris in “ Planets and Satellites’', The Solar System, vol. 3, 1961. +Depending on latitude. For the physical observations of the sun, p. 60, the sidereal period of rotation is 25.38 m.s.d. ++Mariner II, Dec. 14, 1962. § Radar, 1965. SATELLITES OF THE SOLAR SYSTEM

Mean Distance Revolution Orbit Mag. Diam. from Planet Period Inch Discovery miles * t t miles | " * d h m ° t

SATELLITE OF THE EARTH Moon - 1 2 .7 | 2160 238,900| . .. | 27 07 431 Var.§

S a t e l l it e s o f M a r s Phobos 11.6 (10) 5,800 25 | 0 07 39| 1.0 |Hall, 1877 Deimos 12.8 ( <10) 14,600 62 | 1 06 18| 1.3 |Hall, 1877

S a t e l l it e s o f J u p i t e r V 13.0 (100) 112,000 59 0 11 57 0.4 Barnard, 1892 Io 4.8 2020 262,000 138 1 18 28 0 Galileo, 1610 Europa 5.2 1790 417,000 220 3 13 14 0 Galileo, 1610 4.5 3120 665,000 351 7 03 43 0 Galileo, 1610 Callisto 5.5 2770 1,171,000 618 16 16 32 0 Galileo, 1610 VI 13.7 (50) 7,133,000 3765 250 14 27.6 Perrine, 1904 VII 16 (20) 7,295,000 3850 259 16 24.8 Perrine, 1905 X 18.6 ( <10) 7,369,000 3888 263 13 29.0 Nicholson, 1938 XII 18.8 ( <10) 13,200,000 6958 631 02 147 Nicholson, 1951 XI 18.1 ( <10) 14,000,000 7404 692 12 164 Nicholson, 1938 VIII 18.8 ( <10) 14,600,000 7715 738 22 145 Melotte, 1908 IX 18.3 ( <10) 14,700,000 7779 758 153 Nicholson, 1914

S a t e l l it e s o f S a t u r n Mimas 12.1 300: 116,000 30 0 22 37 1.5 W. Herschel, 1789 Enceladus 11.8 400: 148,000 38 1 08 53 0.0 W. Herschel, 1789 Tethys 10.3 600 183,000 48 1 21 18 1.1 G. Cassini, 1684 Dione 10.4 600: 235,000 61 2 17 41 0.0 G. Cassini, 1684 Rhea 9.8 810 327,000 85 4 12 25 0.4 G. Cassini, 1672 Titan 8.4 2980 759,000 197 15 22 41 0.3 Huygens, 1655 Hyperion 14.2 (100) 920,000 239 21 06 38 0.4 G. Bond, 1848 Iapetus 11.0 (500) 2,213,000 575 79 07 56 14.7 G. Cassini, 1671 Phoebe (14) (100) 8,053,000 2096 550 11 150 W. Pickering, 1898

S a t e l l it e s o f U r a n u s Miranda 16.5 (200) 77,000 9 1 09 56 0 Kuiper, 1948 Ariel 14.4 (500) 119,000 14 2 12 29 0 Lassell, 1851 Umbriel 15.3 (300) 166,000 20 4 03 38 0 Lassell, 1851 Titania 14.0 (600) 272,000 33 8 16 56 0 W. Herschel, 1787 Oberon 14.2 (500) 365,000 44 13 11 07 0 W. Herschel, 1787

S a t e l l it e s o f N e p t u n e Triton | 13.6 | 2300 | 220,000| 17 | 5 21 03| 160.0 |Lassell, 1846 Nereid | 18.7 | (200) | 3,461,000| 264 |359 10 | 27.4 |Kuiper, 1949 *At mean opposition distance. +From D. L. Harris in “Planets and Satellites”, The Solar System, vol. 3, 1961, except numbers in brackets which are rough estimates. ++Inclination of orbit referred to planet’s equator; a value greater than 90° indicates retrograde motion. §Varies 18° to 29°. The eccentricity of the mean is 0.05490. Satellites Io, Europa, Ganymede, Callisto are usually denoted I, II, III, IV res­ pectively, in order of distance from the planet. SOLAR, SIDEREAL AND EPHEMERIS TIME Any recurring event may be used to measure time. The various times commonly used are defined by the daily passages of the sun or stars caused by the rotation of the earth on its axis. The more uniform revolution of the earth about the sun, causing the return of the seasons, defines ephemeris time. A sun-dial indicates apparent solar time, but this is far from uniform because of the earth’s elliptical orbit and the inclination of the ecliptic. If the real sun is replaced by a fictitious mean sun moving uniformly in the equator, we have mean (solar) time. Apparent time —mean time — equation of time. This is the same as correction to sun-dial on page 7, with reversed sign. If instead of the sun we use stars, we have sidereal time. The sidereal time is zero when the vernal equinox or first of Aries is on the meridian. As the earth makes one more revolution with respect to the stars than it does with respect to the sun, sidereal time gains on mean time 3m56s per day or 2 hours per month. Right Ascension (R.A.) is measured east from the vernal equinox, so that the R.A. of a body on the meridian is equal to the sidereal time. Sidereal time is equal to mean time plus 12 hours plus the R.A. of the fictitious mean sun, so that by observation of one kind of time we can calculate the other. Sidereal time = Standard time (Oh at midnight) — correction for longitude (p. 12) + 12 h + R. A. sun (p. 7) — correction to sun-dial (p. 7). (Note that it is necessary to obtain R. A. of the sun at the standard time involved.) The foregoing refers to local time, in general different in different places on the earth. The local mean time of Greenwich, now known as Universal Time (UT) is used as a common basis for timekeeping. Navigation and surveying tables are generally prepared in terms of UT. When great precision is required, UT 1 and UT 2 are used differing from UT by polar variation and by the combined effects of polar variation and annual fluctuation respectively. To avoid the inconveniences to travellers of a changing, local time, standard time is used. The earth is divided into 24 zones, each ideally 15 degrees wide, the zero zone being centered on the Greenwich meridian. All clocks within the same zone will read the same time. In Canada and the United States there are 8 standard time zones as follows: Newfoundland (N), 3h30m slower than Greenwich; 60th meridian or Atlantic (A), 4 hours; 75th meridian or Eastern (E), 5 hours; 90th meridian or Central (C), 6 hours; 105th meridian or Mountain (M), 7 hours; 120th meridian or Pacific (P), 8 hours; 135th meridian or Yukon (Y), 9 hours; and 150th meridian or Alaska (AL), 10 hours slower than Greenwich.* Universal time, even after the corrections mentioned have been applied, is still somewhat variable, as shown by atomic clocks or the orbital motion of the moon. Ephemeris Time (ET) is used when these irregularities must be avoided. The second, formerly defined as 1/86,400 of the mean solar day, is now defined as 1/31,556,925.9747 of the tropical year for 1900 Jan. 0 at 12 hours E.T. The difference, AT, between UT and ET is measured as a small error in the observed longitude of the moon, in the sense ΔT = ET — UT. The moon’s position is tabulated in ET, but observed in UT. AT was zero near the beginning of the century, but in 1966 will be about 36 seconds. *Note: The situation in Saskatchewan is confused, with the cities (except Lloydminster) on C.S.T. and many of the towns retaining M.S.T. The time zone boundary between C.S.T. and M.S.T. lies somewhere within the province of Saskatchewan. MAP OF STANDARD TIME ZONES

RADIO TIME SIGNALS Many national observatories and some standards laboratories transmit time signals. A complete listing of stations emitting time signals may be found in the “List of Radiodetermination and Special Service Stations” prepared by the General Secretariat of the International Telecommunication Union, Geneva. For use in Canada and adjacent areas, the following is a brief list of controlled frequency stations. CHU Ottawa, Canada—3330, 7335, 14670 kilocycles WWV Beltsville, Maryland—2.5, 5, 10, 15, 20, 25 megacycles WWVH Maui, Hawaii—5, 10, 15 megacycles NBA Balboa, Canal Zone—18 kilocycles. TIMES OF RISING AND SETTING OF THE SUN AND MOON The times of sunrise and sunset for places in latitudes ranging from 32° to 54° are given on pages 13 to 18, and of twilight on page 19. The times of moonrise and moonset for the 5 h meridian are given on pages 20 to 25. The times are given in Local Mean Time, and in the table below are given corrections to change from Local Mean Time to Standard Time for the cities and towns named. The tabulated values are computed for the sea horizon for the rising and setting of the upper limb of the sun and moon, and are corrected for refraction. Because variations from the sea horizon usually exist on land, the tabulated times can rarely be observed.

The Standard Times for Any Station To derive the Standard Time of rising and setting phenomena for the places named, from the list below find the approximate latitude of the place and the correction in minutes which follows the name. Then find in the monthly table the Local Mean Time of the phenomenon for the proper latitude on the desired day. Finally apply the correction to get the Standard Time. The correction is the number of minutes of time that the place is west (plus) or east (minus) of the standard meridian. The corrections for places not listed may be obtained by con­ verting the longitude found from an atlas into time (360° = 24 h).

CANADIAN CITIES AND TOWNS AMERICAN CITIES

Lat. Corr. Lat. Corr. Lat. Corr. A thabaska 55° +33M Penticton 49° — 02P A tlanta 34° + 3 7 E Baker Lake 64 + 24C Peterborough 44 + 13E Baltimore 39 + 0 6 E Brandon 50 + 40C Port Harrison 59 + 13E Birmingham 33 — 13C Brantford 43 + 21E Port Arthur 48 + 57E Boston 42 — 16E Calgary 51 T36M Prince Albert 53 +03M Buffalo 43 + 15E Charlottetown 46 + 12A Prince Rupert 54 +41P Chicago 42 -10C Churchill 60 + 17C Quebec 47 - 1 5 E Cincinnati 39 + 38E Cornwall 45 - 1E Regina 50 — 02M Cleveland 42 + 26E Edm onton 54 + 34M St. Catharines 43 + 17E Dallas 33 + 27C Fort William 48 + 57E St. Hyacinthe 46 — 08E Denver 40 00 M Fredericton 46 + 27 A Saint John, N.B. 45 + 24 A D etroit 42 + 32E Gander 49 + 8N St. John’s, Nfld. 48 + 0 1 N Fairbanks 65 — 10AL Glace Bay 46 00A Sarnia 43 + 29E Flagstaff 35 + 27M Goose Bay 53 + 2A Saskatoon 52 + 07M Indianapolis 40 — 15C Granby 45 — 09E Sault Ste. Marie 47 + 37E Juneau 58 + 58P Guelph 44 + 21E Shawinigan 47 — 09E Kansas City 39 + 18C Halifax 45 + 14A Sherbrooke 45 — 12E Los Angeles 34 — 07P Hamilton 43 + 20E Stratford 43 + 24E Louisville 38 — 17C Hull 45 + 03E Sudbury 47 + 24E Memphis 35 00C Kapuskasing 49 + 30E Sydney 46 +01A Miami 26 + 21E Kingston 44 + 0 6 E The Pas 54 + 45C Milwaukee 43 -0 9 C K itchener 43 + 22E Timmins 48 + 26E Minneapolis 45 + 13C London 43 + 25E Toronto 44 + 18E New Orleans 30 00C Medicine Hat 50 + 23M Three Rivers 46 -10E New York 41 -0 4 E M oncton 46 + 19A Trail 49 — 09P Omaha 41 +24C M ontreal 46 — 06E Truro 45 + 13A Philadelphia 40 + 0 1 E Moosonee 51 + 23E Vancouver 49 + 12P Phoenix 33 + 28M Moose Jaw 50 + 02M Victoria 48 + 13P Pittsburgh 40 + 20E Niagara Falls 43 + 16E W hitehorse 61 00Y St. Louis 39 + 01C North Bay 46 + 18E Windsor 42 + 32E San Francisco 38 + 10P Ottaw a 45 + 03E Winnipeg 50 + 29C Seattle 48 + 09P Owen Sound 45 + 24E Yellowknife 62 + 38M W ashington 39 + 0 8 E

Example—Find the time of sunrise at Owen Sound, on February 12. In the above list Owen Sound is under “45°”, and the correction is + 24 min. On page 13 the time of sunrise on February 12 for latitude 45° is 7.07; add 24 min. and we get 7.31 (Eastern Standard Time). Latitude 32° Latitude 36° Latitude 40° Latitude 44° Latitude 46° Latitude 48° Latitude 50° Latitude 54: DATE Sunrise Sunset Sunrise Sunset Sunrise Sunset Sunrise Sunset Sunrise Sunset Sunrise Sunset Sunrise Sunset Sunrise Sunset

BEGINNING OF MORNING AND ENDING OF EVENING TWILIGHT

The above table gives the local mean time of the beginning of morning twilight, and of the ending of evening twilight, for various latitudes. To obtain the corresponding standard time, the method used is the same as for correcting the sunrise and sunset tables, as described on page 12. The entry ---- in the above table indicates that at such dates and latitudes, twilight lasts all night. This table, taken from the American Ephemeris, is computed for astronomical twilight, i.e. for the time at which the sun is 108° from the zenith (or 18° below the horizon). TIM E OF MOONRISE AND MOONSET, 1966 (Local Mean Time)

THE SUN AND PLANETS FOR 1966

THE SUN The diagram represents the sun-spot activity of the current 19th cycle, as far as the final numbers are available. The present cycle began at the minimum in April 1954. For comparison, cycle 18 which began February 1944 (solid curve), and the mean of cycles 8 to 18 (dashed curve), are placed with their minima on April 1954. The present cycle reached its maximum in January 1958 and since then has been declining slowly with the minimum in 1964. The observations for sun-spot numbers may be performed by devoted amateur astronomers with small-sized telescopes (suitably protected). Here is a field for amateurs who wish to make a valuable contribution to solar astronomy.

MERCURY Mercury is exceptional in many ways. It is the planet nearest the sun and travels fastest in its orbit, its speed varying from 23 mi. per sec. at aphelion to 35 mi. per sec. at perihelion. The amount of heat and light from the sun received by it per square mile is, on the average, 6.7 times the amount received by the earth. By a radar technique in 1965, the period of rotation on its axis was found to be 59 days. Mercury’s orbit is well within that of the earth, and the planet, as seen from the earth, appears to move quickly from one side of the sun to the other several times in the year. Its quick motion earned for it the name it bears. Its greatest (i.e., its maximum angular distance from the sun) varies between 18° and 28°, and on such occasions it is visible to the for about two weeks. When the elongation of Mercury is east of the sun it is an evening star, setting soon after the sun. When the elongation is west, it is a morning star and rises shortly before the sun. Its brightness when it is treated as a star is considerable but it is always viewed in the twilight sky and one must look sharply to see it. The most suitable times to observe Mercury are at an eastern elongation in the spring and at a western elongation in the autumn. The dates of greatest elongation this year, together with the planet’s separation from the sun and its stellar magnitude, are given in the following table:

MAXIMUM ELONGATIONS OF MERCURY DURING 1966

Elong. East-—Evening Sky Elong. West-—Morning Sky Date Dist. Mag. Date Dist. Mag.

Mar. 4 18° -0.1 Apr. 18 28° +0.6 June 30 26° + 0 .7 Aug. 16 19° + 0 .2 Oct. 26 24° +0.1 Dec. 4 21° - 0 .2

The most favourable elongations are: in the evening, Mar. 4; in the morning. Dec. 4. The apparent diameter of the planet ranges from about 5" to 11".

VENUS Venus is the next planet in order from the sun. In size and mass it is almost a twin of the earth. Venus being within the earth’s orbit, its apparent motion is similar to Mercury’s but much slower and more stately. The is almost circular with radius of 67 million miles, and its orbital speed is 22 miles per sec. On Jan. 1, 1966, Venus is brilliant (mag. —4.3) low in the south-western sky at sunset; its declination is —16°. It reaches inferior conjunction on Jan. 26 and moves into the morning sky. Greatest brilliancy, mag. —4.3, occurs on Mar. 1, and greatest western elongation, 46°, on April 6, when it crosses the meridian almost 3 hours before the sun at declination —11°. Superior conjunction occurs on Nov. 8. At the end of the year it is still close to the sun in the evening sky. Its brilliance is largely due to dense clouds enshrouding the planet. On Dec. 14, 1962, the American , Mariner II, passed within 21,700 mi. of Venus, sending back over 90 million bits of information. Among its notable discoveries were: surface temperatures up to 800° F.; an atmosphere 10 to 20 times denser than earth’s; no magnetic field or radiation belt; and a rotation period of 225 days (equal to its period of revolution). The apparent diameter of the planet ranges from 63" on Jan. 25 to 10" in Oct. and Nov. MARS The orbit of Mars is outside that of the earth and consequently its planetary phenomena are quite different from those of the two inferior planets discussed above. Its mean distance from the sun is 141 million miles and the eccentricity of its orbit is 0.093, and a simple computation shows that its distance from the sun ranges between 128 and 154 million miles. Its distance from the earth varies from 35 to 235 million miles and its brightness changes accordingly. When Mars is nearest it is conspicuous in its fiery red, but when farthest away it is no brighter than Polaris. Unlike Venus, its atmosphere is very thin, and features on the solid surface are distinctly visible. Utilizing them its rotation period of 24h. 37m. 22.6689s. has been accurately determined. Perhaps the most surprising result of the space programme so far is the revelation by Mariner IV that the surface of Mars contains craters much like those on the Moon. The sidereal, or true mechanical, period of revolution of Mars is 687 days; and the synodic period (for example, the interval from one opposition to the next one) is 780 days. This is the average value; it may vary from 764 to 810 days. At the opposition on Sept. 10, 1956, the planet was closer to the earth than it will be for some years. In contrast, the opposition distance on Mar. 9, 1965, is almost a maximum. On Jan. 1, 1966, Mars is in the evening sky, but is too close to the sun for observation, conjunction occurring on Apr. 29. It gradually emerges into the morning sky and by the end of the year it is in Virgo, crossing the meridian almost 6 hours before the sun. Its stellar magnitude is +1.1. See the map. The apparent diameter of the planet ranges from 3.8" at mid-year to 6.6" at year end.

JUPITER Jupiter is the giant of the family of the sun. Its mean diameter is 87,000 miles and its mass is 2½ times that of all the rest of the planets combined! Its mean distance is 483 million miles and the revolution period is 11.9 years. This planet is known to possess 12 satellites, the last discovered in 1951 (see p. 9). Bands of clouds may be observed on Jupiter, interrupted by irregular spots which may be short-lived or persist for weeks. The atmosphere contains ammonia and methane at a temperature of about — 200°F. Intense radiation belts (like terrestrial Van Allen belts) have been disclosed by observations at radio wave-lengths. Jupiter is a fine object for the telescope. Many details of the cloud belts as well as the flattening of the planet, due to its short rotation period, are visible, and the phenomena of its satellites provide a continual interest. On Jan. 1, 1966, Jupiter is retrograding in Taurus and is low in the east at sunset; its stellar magnitude is —2.3. Direct motion resumes Feb. 15. On July 5 it is in conjunction with the sun and moves into the morning sky. Retrograde motion commences on Nov. 21 and continues for the rest of the year. (See map; circles with vertical lines denote retrograde motion.) At the end of the year it is in Cancer, rising about 3 hours after sunset and visible the rest of the night; its stellar magnitude is —2.1. The apparent diameter of the planet is 44" on Jan. 1, decreases to 30" in early July, and is 42" on Dec. 31.

SATURN Saturn was the outermost planet known until modern times. In size it is a good second to Jupiter. In addition to its family of nine satellites, this planet has a unique system of rings, and it is one of the finest of celestial objects in a good telescope. The plane of the rings makes an angle of 27° with the plane of the planet’s orbit, and twice during the planet’s revolution period of 29| years the rings appear to open out widest; then they slowly close in until, midway between the maxima, the rings are presented edgewise to the sun or the earth, at which times they are invisible. The rings were edgewise in 1950, and will be again in 1966; the northern face of the rings was at maximum in 1958 and the southern will be in 1973. See p. 59. During 1966 Saturn crosses from Aquarius into Pisces, and on Jan. 1 it is just past the meridian at sunset; its stellar magnitude is +1.3 and its declination is — 9°. On Mar. 10 it is in conjunction with the sun and moves into the morning sky. It reaches opposition by Sept. 19, when its stellar magnitude brightens to +0.8 and it is visible all night. It retrogrades from July 12 to Nov. 27 (see map; circles with vertical lines denote retrograde motion). At the end of the year it has stellar magnitude +1.4 and is nearing the meridian at sunset. The apparent diameter of the ball of the planet ranges from 14" in early Mar. to 17" in late Sept.

URANUS Uranus was discovered in 1781 by Sir William Herschel by means of a 6¼-in. mirror-telescope made by himself. The object did not look just like a star and he observed it again four days later. It had moved amongst the stars, and he assumed it to be a . He could not believe that it was a new planet. How­ ever, computation later showed that it was a planet nearly twice as far from the sun as Saturn. Its period of revolution is 84 years and it rotates on its axis in about 11 hours. Its five satellites are visible only in a large telescope.

During 1966 Uranus is in Leo and Virgo (see map). At the beginning of the year it rises before midnight and is retrograding (direct motion resumes on May 23). It is in opposition on Mar. 8 and is above the horizon all night; its apparent diameter is 4.0"; its stellar magnitude is +5.7. When conjunction occurs on Sept. 13 its magnitude has faded to +5.9. It is in the morning sky the rest of the year; retrograde motion commences on Dec. 30. It is overtaken by Venus on Sept. 25, while Mars is close to it during November with conjunction occurring on Nov. 21. NEPTUNE Neptune was discovered in 1846 after its existence in the sky had been pre­ dicted from independent calculations by Leverrier in France and Adams in England. It caused a sensation at the time. Its distance from the sun is 2791 million miles and its period of revolution is 165 years. A satellite was discovered in 1846 soon after the planet. A second satellite was discovered by G. P. Kuiper at the McDonald Observatory on May 1, 1949. Its magnitude is about 19.5, its period about a year, and diameter about 200 miles. It is named Nereid. During 1966 Neptune is in Libra (see map). It is in opposition on May 11, when it is above the horizon all night. Its stellar magnitude is then +7.7 and during the year fades slightly to +7.8. Thus it is too faint to be seen with the naked eye. In the telescope it shows a greenish tint and an apparent diameter 2.5" to 2.3". It is in conjunction with the sun on Nov. 14 and moves into the morning sky for the rest of the year. It retrogrades from Feb. 22 to Aug. 1.

PLUTO Pluto, the most distant known planet, was discovered at the Lowell Observatory in 1930 as a result of an extended search started two decades earlier by Percival Lowell. The faint star-like image was first detected by Clyde Tombaugh by comparing photographs taken on different dates. Further observations con­ firmed that the object was a distant planet. Its mean distance from the sun is 3671 million miles and its revolution period is 248 years. It appears as a 15th mag. star in the constellation Leo. It is in opposition to the sun on Mar. 8, at which time its astrometric position is R.A. 11h 36m, Dec. +18° 56'.

24" X 36" photographic quality prints of plates from the world’s great observa­ tories. On heavy matte finish paper; vinyl coated. Standard prints. $6.00 each. Set of ten shown, $50.00, postpaid.

ASTRO-MURALS P.O. Box 7563 Washington, D.C. 20044 THE SKY MONTH BY MONTH

B y J o h n F. H e a r d

THE SKY FOR JANUARY 1966

Positions of the sun and planets are given for Oh Greenwich Ephemeris Time. The times of at the 75th meridian are given in local mean time, Oh at midnight; to change to Standard Time, see p. 10. Estimates of altitude are for an observer in latitude 45° N. The Sun—During January, the sun’s R.A. increases from 18h 44m to 20h 57m and its Decl. changes from 23° 04' S. to 17° 17' S. The equation of time changes from —3m 36s to —13m 30s. These values of the equation of time are for noon E.S.T. on the first and last days of the month in this and in following months. The earth is at perihelion or nearest the sun on the 3rd, at a distance of 91,346,000 mi. For changes in the length of the day, see p. 13. The Moon—For its phases, perigee and apogee times and distances, and its conjunctions with the planets, see opposite page. Times of moonrise and moonset are given on p. 20. Mercury on the 1st is in R.A. 17h 19m, Decl. 22° 20' S. and on the 15th is in R.A. 18h 47m, Decl. 23° 5 7 'S., when it transits at 11h 12m. It is too close to the sun for observation. Venus on the 1st is in R.A. 21h 02m, Decl. 15° 48' S. and on the 15th is in R.A. 20h 53m, Decl. 12° 5 5 'S., when it has mag. —3.8, and transits at 13h 12m. For the first half of the month it is visible as an evening star very low in the south-west after sunset, but later it is too close to the sun for observation, being in inferior conjunction on the 26th. Mars on the 15th is in R.A. 21h 23m, Decl. 16° 31' S., and transits at 13h 46m. It is too close to the sun for observation. Jupiter on the 15th is in R.A. 5h 29m, Decl. 22° 56' N., mag. —2.2, and transits at 21h 47m. In Taurus, it is well up in the east by sunset and is visible most of the night. For the configurations of Jupiter’s satellites see opposite page, and for their eclipses, etc., see p. 56. Saturn on the 15th is in R.A. 23h 03m, Decl. 8° 12' S., mag. +1.3, and transits at 15h 23m. In Aquarius, is past the meridian at sunset and sets about three hours later. Uranus on the 15th is in R.A. 11h 22m, Decl. 4° 55' N., and transits at 3h 44m. Neptune on the 15th is in R.A. 15h 19m, Decl. 18° 33' S., and transits at 7h 41m. Pluto—For information in regard to this planet, see p. 31. Config. of Sun’s JANUARY Min. Jupiter’s Selen. E.S.T. of Sat. Colong. Algol 23h 10m 0h U.T.

Sat. 1 Sun. 2 Mon. 3 Earth at perihelion...... Quadrantid meteors...... Venus stationary...... Tue. 4 Wed. 5 Jupiter 2° S. of m oon...... Thu. 6 Mercury at descending node.... Fri. 7 Full M oon...... Sat. 8 Venus 4° N. of M ars...... Moon at perigee, 223,100 mi. . . . Sun. 9 Mon. 10 Tue. 11 Uranus 5° S. of m oon...... Wed. 12 Thu. 13 C Last Q uarter...... Fri. 14 Sat. 15 Neptune 0.7° N. of moon...... Sun. 16 Mars at perihelion...... Mon. 17 Mercury at aphelion...... Tue. 18 Wed. 19 Thu. 20 Fri. 21 New M oon...... Sat. 22 Sun. 23 M ars 4° N. of m oon...... Moon at apogee, 252,600 mi...... Mon. 24 Tue. 25 Saturn 3° N. of moon...... Wed. 26 Venus in inferior conjunction. . . Thu. 27 Fri. 28 Sat. 29 Venus at perihelion...... 1 First Quarter...... Sun. 30 Mon. 31

Explanation of abbreviations on p. 4, of time on p. 10, of colongitude on p. 61. lJan. 3, -7 .1 3 °; Jan. 15, +7.10°; Jan. 31, -7.89°. bJan. 10, -6 .6 1 °; Jan. 24, +6.61°. Positions of the sun and planets are given for Oh Greenwich Ephemeris Time. The times of transit at the 75th meridian are given in local mean time, Oh at midnight; to change to Standard Time, see p. 10. Estimates of altitude are for an observer in latitude 45° N. The Sun—During February the sun’s R.A. increases from 20h 57m to 22h 46m and its Decl. changes from 17° 17' S. to 7° 50' S. The equation of time changes from — 13m 39s to a maximum of — 14m 18s on the 11th and then to — 12m 37s at the end of the month. For changes in the length of the day, see p. 13. The Moon—For its phases, perigee and apogee times and distances, and its conjunctions with the planets, see opposite page. Times of moonrise and moonset are given on p. 20. Mercury on the 1st is in R.A. 20h 44m, Decl. 20° 15' S. and on the 15th is in R.A. 22h 22m, Decl. 11° 56' S., when it transits at 12h 45m. It is too close to the sun for observation until month-end; superior conjunction is on the 5th. Venus on the 1st is in R.A. 20h 12m, Decl. 12° 10' S., and on the 15th is in R.A. 19h 55m, Decl. 13° 13'S., when it has mag. —4.1, and transits at 10h 14m. Towards mid-month it begins to be observable as a morning star very low in the south-east just before sunrise. Mars on the 15th is in R.A. 22h 56m, Decl. 7° 46' S., and transits at 13h 17m. It is too close to the sun for observation. Jupiter on the 15th is in R.A. 5h 22m, Decl. 22° 56' N., mag. —2.0, and transits at 19h 39m. In Taurus, it is high in the eastern sky at sunset and is visible most of the night. On the 15th it is stationary in right ascension and resumes direct, i.e. eastward, motion among the stars. For the configurations of Jupiter’s satellites see opposite page, and for their eclipses, etc., see p. 56. Saturn on the 15th is in R.A. 23h 15m, Decl. 6° 53' S., and transits at 13h 33m. In Aquarius, it is well down in the west at sunset. Uranus on the 15th is in R.A. 11h 19m, Decl. 5° 18' N., and transits at 1h 39m. Neptune on the 15th is in R.A. 15h 21m, Decl. 16° 37' S., and transits at 5h 40m. Pluto—For information in regard to this planet, see p. 31. Config. of Sun’s FEBRUARY Min. Jupiter’s Selen. of Sat. Colong. E.S.T. Algol 22h 30m 0h U.T.

Jupiter 2° S. of moon......

0 Full Moon...... Moon at perigee, 221,500 m i.. . . Mercury in superior conjunction. Mercury greatest hel. lat. S...... Uranus 4° S. of moon......

Neptune in quadrature W...... Neptune 1° N. of moon...... Last Quarter......

Vesta stationary...... Jupiter stationary...... Venus stationary......

Venus 12° N. of moon......

Moon at apogee, 252,700 mi...... Venus greatest hel. lat. N ...... New Moon...... Mars 4° N. of moon...... Saturn 3° N. of moon...... Mars 1.1° N. of Saturn...... Neptune stationary...... Mercury 1.7° N. of Saturn...... Mercury 0.7° N. of M ars...... Mercury at ascending node......

First Quarter......

Explanation of abbreviations on p. 4, of time on p. 10, of colongitude on p. 61. lFeb. 12, +7.74°; Feb. 28, -7.73°. bFeb. 7, -6.48°; Feb. 20, +6.54°. Positions of the sun and planets are given for Oh Greenwich Ephemeris Time. The times of transit at the 75th meridian are given in local mean time, Oh at midnight; to change to Standard Time, see p. 10. Estimates of altitude are for an observer in latitude 45° N. The Sun—During March the sun’s R.A. increases from 22h 46m to Oh 40m and its Decl. changes from 7° 50' S. to 4° 17' N. The equation of time changes from — 12m 26s to —4m 14s. On the 20th at 20h 53m E.S.T. the sun crosses the equator on its way north, enters the sign of Aries, and spring commences. This is the vernal equinox. For changes in the length of the day, see p. 14. The Moon—For its phases, perigee and apogee times and distances, and its conjunctions with the planets, see opposite page. Times of moonrise and moonset are given on p. 21. Mercury on the 1st is in R.A. 23h 48m, Decl. 0° 24' S., and on the 15th is in R.A. 0h 13m, Decl. 5° 14' N., when it transits at 12h 40m. On the 4th it is at greatest eastern elongation and stands about 16 degrees above the western horizon at sunset. For about a week at this time it may be seen low in the west just after sunset. On the 21st it is in inferior conjunction. Venus on the 1st is in R.A. 20h 09m, Decl. 14° 11' S., and on the 15th is in R.A. 20h 46m, Decl. 14° 01' S., when it has mag. —4.2, and transits at 9h 16m. It is a morning star visible low in the south-east for about an hour before sunrise. Greatest brilliancy is on the 1st. Mars on the 15th is in R.A. 10h 17m, Decl. 1° 04' N., and transits at 12h 47m. It is too close to the sun for observation. Jupiter on the 15th is in R.A. 5h 27m, Decl. 23° 05' N., mag. —1.8, and transits at 17h 55m. In Taurus, it is about on the meridian at sunset and sets about an hour after midnight. For the configurations of Jupiter’s satellites see opposite page, and for their eclipses, etc., see p. 56. Saturn on the 15th is in R.A. 23h 28m, Decl. 5° 33' S., and transits at 11h 56m. Conjunction is on the 10th and Saturn is too close to the sun all month for easy observation. Uranus on the 15th is in R.A. 11h 15m, Decl. 5° 46' N., mag. 5.7 and transits at 23h 41m. Opposition is on the 8th, at which time its distance from the earth is 1,606,000,000 mi. Neptune on the 15th is in R.A. 15h 21m, Decl. 16° 34' S., and transits at 3h 50m. Pluto—For information in regard to this planet, see p. 31. Config. of Sun’s MARCH M in. Jupiter’s Selen. of Sat. Colong. E.S.T. Algol 21h 50m 0h U .T .

Jupiter 2° S. of moon...... Pallas in conjunction with sun. . Venus at greatest brilliancy...... Mercury at perihelion......

Mercury greatest elong. E., 18° .

Moon at perigee, 222,000 mi...... Full Moon...... Uranus 4° S. of moon......

Pluto at opposition...... Uranus at opposition......

Saturn in conjunction with sun.. Mercury stationary...... Neptune 1° N. of moon...... Mercury greatest hel. lat. N ...... Jupiter in quadrature E ...... Last Quarter...... Mercury 4° N. of M ars......

Venus 9° N. of moon...... Moon at apogee, 252,400 mi......

Equinox. Spring begins...... Mercury in inferior conjunction. New Moon......

Jupiter 3° S. of moon...... First Quarter...... Mercury 3° N. of Saturn......

Explanation of abbreviations on p. 4, of time on p. 10, of colongitude on p. 61. lMar. 12, +7.48°; Mar. 28, -6.78°. bMar. 6, -6.52°; Mar. 19, +6.61°. Positions of the sun and planets are given for Oh Greenwich Ephemeris Time. The times of transit at the 75th meridian are given in local mean time, 0h at midnight; to change to Standard Time, see p. 10. Estimates of altitude are for an observer in latitude 45° N. The Sun—During April the sun’s R.A. increases from 0h 40m to 2h 31m and its Decl. changes from 4° 17' N. to 14° 52' N. The equation of time changes from — 3m 56s to +2m 49s, being zero on the 15th. For changes in the length of the day, see p. 14. The Moon—For its phases, perigee and apogee times and distances, and its conjunctions with the planets, see opposite page. Times of moonrise and moonset are given on p. 21. Mercury on the 1st is in R.A. 23h 34m, Decl. 1° 49' S., and on the 15th is in R.A. 23h 54m, Decl. 2° 48' S., when it transits at 10h 22m. On the 18th it is at greatest western elongation, but this is an unfavourable elongation, Mercury being only about 10 degrees above the eastern horizon at sunrise. Venus on the 1st is in R.A. 21h 45m, Decl. 11° 45' S., and on the 15th is in R.A. 22h 40m, Decl. 8° 14' S., when it has mag. —3.9, and transits at 9h 08m. Greatest western elongation is on the 6th, but even so it is only about 18 degrees above the south-eastern horizon at sunrise. Mars on the 15th is in R.A. 1h 44m, Decl. 10° 23' N., and transits at 12h 12m. It is too close to the sun for observation and on the 29th it is in conjunction. Jupiter on the 15th is in R.A. 5h 44m, Decl. 23° 19' N., mag. —1.6, and transits at 16h 10m. Moving from Taurus into Gemini, it is past the meridian at sunset and sets before midnight. For the configurations of Jupiter’s satellites see opposite page, and for their eclipses, etc., see p. 56. Saturn on the 15th is in R.A. 23h 41m, Decl. 4° 08' S., mag. +1.4, and transits at 10h 08m. It is a morning star rising about an hour before the sun. The earth is in the plane of the rings on the 2nd. Uranus on the 15th is in R.A. 11h 10m, Decl. 6° 13' N., and transits at 21h 34m. Neptune on the 15th is in R.A. 15h 18m, Decl. 16° 24' S., and transits at 1h 46m. Pluto—For information in regard to this planet, see p. 31. Config. of Sun’s APRIL M in. Ju p iter’s Selen. of Sat. Colong. E.S.T. Algol 21h 20m 0h U .T.

Mercury stationary...... Uranus 4° S. of moon...... Moon at perigee, 224,300 m i. . . . Mercury at descending node.... Full Moon...... Venus greatest elong. W., 46°. .. Juno in conjunction with sun. . . Neptune 2° N. of moon...... Mercury 1.0° N. of S a tu rn ......

Last Quarter......

Mercury at aphelion...... Moon at apogee, 251,800 mi.... Venus 6° N. of moon...... Venus at descending node...... Saturn 3° N. of moon...... Mercury 2° N. of moon...... Mercury greatest elong. W., 28°.

New Moon......

Lyrid meteors......

Jupiter 3° S. of moon......

First Quarter......

Mars in conjunction with sun. .. in conjunction with sun ... Uranus 5° S. of moon......

Explanation of abbreviations on p. 4, of time on p. 10, of colongitude on p. 61. lApr. 9, + 6.54°; Apr. 24, -5.57°. bApr. 2, -6.63°; Apr. 16, +6.75°; Apr. 29, —6.71°. Positions of the sun and planets are given for Oh Greenwich Ephemeris Time. The times of transit at the 75th meridian are given in local mean time, 0h at midnight; to change to Standard Time, see p. 10. Estimates of altitude are for an observer in latitude 45° N. The Sun—During May the sun's R.A. increases from 2h 31m to 4h 34m and its Decl. changes from 14° 52' N. to 21° 58' N. The equation of time changes from +2m 56s to a maximum of +3m 45s on the 14th and then to + 2m 27s at the end of the month. For changes in the length of the day, see p. 15. There is an annular eclipse, not visible in North America, on the 20th. The Moon—For its phases, perigee and apogee times and distances, and its conjunctions with the planets, see opposite page. Times of moonrise and moonset are given on p. 22. There is a penumbral eclipse on the 4th, not visible in North America. Mercury on the 1st is in R.A. 1h 04m, Decl. 3° 46' N., and on the 15th is in R.A. 2h 32m, Decl. 13° 18' N., when it transits at 11h 05m. It is too close to the sun for observation; superior conjunction is on the 27th. Venus on the 1st is in R.A. 23h 45m, Decl. 2° 47' S., and on the 15th is in R.A. Oh 43m, Decl. 2°43'N ., when it has mag. —3.6, and transits at 9h 13m. It is visible as a morning star low in the east for about two hours before sunrise. Mars on the 15th is in R.A. 3h 10m, Decl. 17° 43' N., and transits at 11h 40m. It is too close to the sun for observation. Jupiter on the 15th is in R.A. 6h 08m, Decl. 23° 24' N., mag. —1.5, and transits at 14h 36m. In Gemini, it is well down in the west at sunset and sets about three hours later. For the configurations of Jupiter’s satellites see opposite page, and for their eclipses, etc., see p. 56. Saturn on the 15th is in R.A. 23h 52m, Decl. 3° 01' S., mag. +1.4, and transits at 8h 21m. In Pisces, it rises about two hours before the sun. Uranus on the 15th is in R.A. 11h 08m, Decl. 6° 26' N., and transits at 19h 34m. Neptune on the 15th is in R.A. 15h 15m, Decl. 16° 12' S., mag. 7.7, and transits at 23h 41m. Opposition is on the 11th, at which time its distance from the earth is 2,723,000,000 mi. Pluto—For information in regard to this planet, see p. 31. Config. of Sun’s MAY M in. Ju p iter’s Selen. of Sat. Colong. E.S.T. Algol 20h 50m 0h U.T.

Moon at perigee, 227,600 mi. ... Venus 1.0° N. of Saturn......

Full Moon...... Penumbral eclipse of , p. 64 Aquarid meteors...... Mercury greatest hel. lat. S...... Neptune 2° N. of moon......

Neptune at opposition...... G Last Quarter...... Moon at apogee, 251,300 mi... .

Saturn 3° N. of moon...... Venus 2° N. of moon......

Mars at ascending node......

Uranus at perihelion...... New Moon...... Annular eclipse of p. 64. . Venus at aphelion...... Jupiter 3° S. of moon...... Uranus stationary...... Mercury at ascending node......

Mercury in superior conjunction. First Quarter...... Moon at perigee, 229,800 mi... . Uranus 5° S. of moon......

Mercury at perihelion...... Jupiter at ascending node......

Explanation of abbreviations on p. 4, of time on p. 10, of colongitude on p. 61. lMay 7, +5.47°; May 20, 21, -5.15°. bMay 13, +6.85°; May 27, -6.74°. Positions of the sun and planets are given for Oh Greenwich Ephemeris Time. The times of transit at the 75th meridian are given in local mean time, 0h at midnight; to change to Standard Time, see p. 10. Estimates of altitude are for an observer in latitude 45° N. The Sun—During June the sun’s R.A. increases from 4h 34m to 6h 38m and its Decl. changes from 21° 58' N. to 23° 09' N. The equation of time changes from +2m 18s to —3m 31s, being zero on the 14th. The solstice is on the 21st at 15h 33m E.S.T. For changes in the length of the day, see p. 15. The Moon—For its phases, perigee and apogee times and distances, and its conjunctions with the planets, see opposite page. Times of moonrise and moonset are given on p. 22. Mercury on the 1st is in R.A.4h 58m, Decl. 23° 55' N., and on the 15th is in R.A. 6h 58m, Decl. 24° 48' N., when it transits at 13h 29m. For about a week at the end of the month it may be seen as an evening star low in the west just after sunset. Greatest eastern elongation is on the 30th at which time the planet stands about 15 degrees above the western horizon at sunset. Venus on the 1st is in R.A. 1h 56m, Decl. 9° 36' N., and on the 15th is in R.A. 2h 59m, Decl. 14° 49' N., when it has mag. —3.5, and transits at 9h 27m. It is visible as a morning star low in the east for about two hours before sunrise. Mars on the 15th is in R.A. 4h 42m, Decl. 22° 32' N., and transits at 11h 09m. It is too close to the sun for observation. Jupiter on the 15th is in R.A. 6h 37m, Decl. 23° 12' N., mag. —1.4, and transits at 13h 03m. In Gemini, at mid-month, it is low in the west at sunset and sets about two hours later; by month’s end it is too close to the sun for observation. Saturn on the 15th is in R.A. 0h 00m, Decl. 2° 19' S., mag. +1.3, and transits at 6h 26m. In Pisces, it rises about four hours before the sun. Uranus on the 15th is in R.A. 11h 09m, Decl. 6° 21' N., and transits at I7h 33m. Neptune on the 15th is in R.A. 15h 12m, Decl. 16° 00' S., and transits at 21h 36m. Pluto—For information in regard to this planet, see p. 31. Sun’s JUNE M in. Selen. of Colong. E.S.T. Algol 0h U.T.

Neptune 1° N. of moon...... Pluto stationary...... Full Moon......

Uranus in quadrature E......

Mercury greatest hel. lat. N ......

Moon at apogee, 251,200 mi... . G Last Quarter...... Mercury 2° N. of Jupiter...... Saturn 2° N. of moon......

Venus greatest hel. lat. S......

Venus 1° S. of moon......

New Moon......

Saturn in quadrature W...... Mercury 3° S. of moon...... Solstice. Summer begins...... Moon at perigee, 227,900 mi. . . .

Uranus 4° S. of moon...... First Quarter......

Neptune 1° N. of moon......

Mercury greatest elong. E., 26°..

Explanation of abbreviations on p. 4, of time on p. 10, of colongitude on p. 61. lJune 4, +4.77°; June 17, -5.74°; June 30, +5.11°. bJune 9, +6.81°; June 23, -6.67°. Jupiter being near the sun, configurations of the satellites are not given between June 1 and August 1. Positions of the sun and planets are given for Oh Greenwich Ephemeris Time. The times of transit at the 75th meridian are given in local mean time, 0h at midnight; to change to Standard Time, see p. 10. Estimates of altitude are for an observer in latitude 45° N. The Sun—During July the sun’s R.A. increases from 6h 38m to 8h 43m and its Decl. changes from 23° 09' N. to 18° 12' N. The equation of time changes from — 3m 43s to —6m 19s. On the 5th the earth is in aphelion or farthest from the sun, 94,448,000 mi. For changes in the length of the day, see p. 16. The Moon—For its phases, perigee and apogee times and distances, and its conjunctions with the planets, see opposite page. Times of moonrise and moonset are given on p. 23. Mercury on the 1st is in R.A. 8h 27m, Decl. 19° 18' N., and on the 15th is in R.A. 8h 52m, Decl. 14° 24' N., when it transits at 13h 18m. For about a week following greatest elongation on June 30th it may be seen as an evening star low in the west just after sunset. Venus on the 1st is in R.A. 4h 15m, Decl. 19° 34' N., and on the 15th is in R.A. 5h 25m, Decl. 22° 05' N., when it has mag. —3.3, and transits at 9h 56m. It is a morning star to be seen low in the east for about two hours before sunrise. Mars on the 15th is in R.A. 6h 11m, Decl. 24° 01' N., and transits at 10h 41m. It is too close to the sun for easy observation. Jupiter on the 15th is in R.A. 7h 06m, Decl. 22° 39' N., mag. —1.4, and transits at 11h 34m. Conjunction is on the 5th, but towards the end of the month it can be seen as a morning star rising about an hour before the sun. Saturn on the 15th is in R.A. 0h 02m, Decl. 2° 13' S., mag. +1.1, and transits at 4h 31m. In Pisces, it rises before midnight and is visible the rest of the night. On the 12th it is stationary in right ascension and begins to retrograde, i.e. move westward among the stars. Uranus on the 15th is in R.A. 11h 12m, Decl. 5° 58' N., and transits at 15h 39m. Neptune on the 15th is in R.A. 15h 10m, Decl. 15° 54' S., and transits at 19h 36m. Pluto—For information in regard to this planet, see p. 31. Sun' JULY M ins. Selen. Colong. E.S.T. Algol 0h U.T.

Mercury at descending node.... Full Moon......

Earth at aphelion...... Jupiter in conjunction with sun

Moon at apogee, 251,600 mi. . . .

Saturn 2° N. of moon...... Last Quarter......

Mercury at aphelion...... Saturn stationary...... Mercury stationary......

Venus 4° S. of moon...... Mars 3° S. of moon...... New Moon......

Moon at perigee, 224,800 mi... .

Uranus 4° S. of moon......

First Quarter...... Neptune 2° N. of moon......

Mercury in inferior conjunction. δ Aquarid meteors......

Explanation of abbreviations on p. 4, of time on p. 10, of colongitude on p. 61. lJuly 14, -6.66°; July 27, +6.29°. bJuly 6, +6.67°; July 20, -6.55°. Jupiter being near the sun, configurations of the satellites are not given between June 1 and August 1. Positions of the sun and planets are given for Oh Greenwich Ephemeris Time. The times of transit at the 75th meridian are given in local mean time, 0h at midnight; to change to Standard Time, see p. 10. Estimates of altitude are for an observer in latitude 45° N. The Sun—During August the sun’s R.A. increases from 8h 43m to 10h 39m and its Decl. changes from 18° 12' N. to 8° 32' N. The equation of time changes from — 6m 16s to — 0m 20s. For changes in the length of the day, see p. 16. The Moon—For its phases, perigee and apogee times and distances, and its conjunctions with the planets, see opposite page. Times of moonrise and moonset are given on p. 23. Mercury on the 1st is in R.A. 8h 15m, Decl. 14° 58' N., and on the 15th is in R.A. 8h 20m, Decl. 18° 07' N., when it transits at 10h 48m. For about a week at mid- month it may be seen as a morning star low on the eastern horizon just before sunrise. Greatest western elongation is on the 16th at which time it stands about 16 degrees above the eastern horizon at sunrise. Venus on the 1st is in R.A. 6h 54m, Decl. 22° 32' N., and on the 15th is in R.A. 8h 06m, Decl. 20° 35' N., when it has mag. —3.3, and transits at 10h 35m. It is a morning star to be seen low in the east for about two hours before sunrise. Mars on the 15th is in R.A. 7h 40m, Decl. 22° 20' N., and transits at 10h 07m. It is a morning star in Gemini rising about two hours before the sun. On the 12th it passes 0.7° N. of Jupiter, and on the 15th is 6° S. of Pollux. Jupiter on the 15th is in R.A. 7h 35m, Decl. 21° 46' N., mag. —1.4, and transits at 10h 01m. In Gemini, it is a morning star rising about two hours before the sun. On the 24th it is 7° S. of Pollux (see Mars.) For the configurations of Jupiter’s satellites see opposite page, and for their eclipses, etc., see p. 56. Saturn on the 15th is in R.A. 23h 59m, Decl. 2° 42' S., mag. +1.0, and transits at 2h 25m. In Pisces it rises about two hours after sunset and is visible the rest of the night. Uranus on the 15th is in R.A. 11h 18m, Decl. 5° 20' N., and transits at 13h 43m. Neptune on the 15th is in R.A. 15h 10m, Decl. 15° 55' S., and transits at 17h 34m. Pluto—For information in regard to this planet, see p. 31.

Explanation of abbreviations on p. 4, of time on p. 10, of colongitude on p. 61. lAug. 11, 12, -7.40°; Aug. 23, +7.35°. bAug. 2, +6.55°; Aug. 16, -6.48°; Aug. 30, +6.55°. Config. of Sun’s AUGUST M in. Ju p iter’s Selen. of Sat. Colong. E.S.T. Algol 18h 45m 0h U .T.

Mercury greatest hel. lat. S...... Full M oon...... Neptune stationary......

Venus 1.0° S. of M ars...... Moon at apogee, 252,200 mi... . Saturn 2° N. of moon......

Mercury stationary...... Venus 0.1° S. of Ju p ite r...... Venus at ascending node...... G Last Quarter......

Perseid meteors...... Neptune in quadrature E ...... Mars 0.7° N. of Jupiter......

Jupiter 4° S. of m oon...... M ars 4° S. of moon...... Venus 4° S. of m oon...... M ercury 6° S. of m oon......

Mercury greatest elong. W., 19°. New M oon...... Moon at perigee, 222,600 m i___ Uranus 4° S. of m oon......

Mercury at ascending node......

N eptune 2° N. of m oon...... First Quarter......

Pallas stationary...... Mercury at perihelion......

Vesta in conjunction with sun... © Full Moon...... Moon at apogee, 252,500 mi.... Positions of the sun and planets are given for Oh Greenwich Ephemeris Time. The times of transit at the 75th meridian are given in local mean time, Oh at midnight; to change to Standard Time, see p. 10. Estimates of altitude are for an observer in latitude 45° N. The Sun—During September the sun’s R.A. increases from 10h 39m to 12h 27m and its Decl. changes from 8° 32' N. to 2° 55' S. The equation of time changes from — 0m 01s to +9m 57s. On the 23rd at 6h 43m E.S.T. the sun crosses the equator moving southward, enters the sign of Libra, and autumn commences. For changes in the length of the day, see p. 17. The Moon—For its phases, perigee and apogee times and distances, and its conjunctions with the planets, see opposite page. Times of moonrise and moonset are given on p. 24. Mercury on the 1st is in R.A. 10h 07m, Decl. 13° 21' N., and on the 15th is in R.A. 11h 47m, Decl. 2° 53' N., when it transits at 12h 14m. It is too close to the sun for observation, superior conjunction being on the 10th. Venus on the 1st is in R.A. 9h 31m, Decl. 15° 39' N., and on the 15th is in R.A. 10h 38m, Decl. 9° 59' N., when it has mag. —3.4, and transits at 11h 04m. It is a morning star to be seen low in the north-east for about an hour before sunrise. Mars on the 15th is in R.A. 9h 03m, Decl. 18° 03' N., and transits at 9h 27m. Moving through Cancer into Leo, it is a morning star rising about three hours before the sun. Jupiter on the 15th is in R.A. 8h 00m, Decl. 20° 45' N., mag. —1.6, and transits at 8h 24m. Moving into Cancer, it rises about four hours before the sun and is well up in the eastern sky by sunrise. For the configurations of Jupiter’s satellites see opposite page, and for their eclipses, etc., see p. 56. Saturn on the 15th is in R.A. 23h 52m, Decl. 3° 37' S., mag. +0.8, and transits at 0h 16m. In Pisces, it rises about at sunset and sets about at sunrise; opposition is on the 19th, the distance from the earth then being 795,200,000 mi. Uranus on the 15th is in R.A. 11h 25m, Decl. 4° 35' N., and transits at 11h 48m. Neptune on the 15th is in R.A. 15h 12m, Decl. 16° 04' S., and transits at 15h 34m. Pluto—For information in regard to this planet, see p. 31. Config. of Sun's SEPTEMBER Min. Jupiter’s Selen. of Sat. Colong. E.S.T. Algol 17h 15m 0h U.T.

Saturn 2° N. of moon......

Mercury greatest hel. lat. N......

(2 Last Quarter......

Venus at perihelion...... Mercury in superior conjunction. Jupiter 5° S. of moon...... Pluto in conjunction with sun.. . Mars 4° S. of moon......

Uranus in conjunction with sun. Venus 4° S. of moon...... Moon at perigee, 221,800 mi. . . . New Moon......

Neptune 2° N. of moon...... Saturn at opposition......

First Quarter......

Equinox. Autumn begins......

Venus 0.8° N. of Uranus......

Mercury at descending node. . . . Moon at apogee, 252,400 mi... . Saturn 2° N. of moon...... Full Moon, Harvest M oon.. .

Explanation of abbreviations on p. 4, of time on p. 10, of colongitude on p. 61. lSept. 9, -7.62°; Sept. 21, +7.71°. bSept. 13, -6.55°; Sept. 26, +6.68°. Positions of the sun and planets are given for Oh Greenwich Ephemeris Time. The times of transit at the 75th meridian are given in local mean time, 0h at midnight; to change to Standard Time, see p. 10. Estimates of altitude are for an observer in latitude 45° N. The Sun—During October the sun’s R.A. increases from 12h 27m to 14h 23m and its Decl. changes from 2° 55' S. to 14° 13' S. The equation of time changes from + 10m 17s to +16m 21s. For changes in the length of the day, see p. 17. The Moon—For its phases, perigee and apogee times and distances, and its conjunctions with the planets, see opposite page. Times of moonrise and moonset are given on p. 24. There is a penumbral eclipse on the night of the 28th-29th, “visible” in North America. Mercury on the 1st is in R.A. 13h 23m, Decl. 9° 09' S., and on the 15th is in R.A. 14h 39m, Decl. 17° 36' S., when it transits at 13h 07m. Greatest eastern elongation is on the 26th, so that the planet might be seen as an evening star, but this is a very unfavourable elongation, Mercury being only about 10 degrees above the south-western horizon at sunset. Venus on the 1st is in R.A. 11h 52m, Decl. 2° 24' N., and on the 15th is in R.A. 12h 57m, Decl. 4° 35' S., when it has mag. —3.5, and transits at 11h 24m. Early in the month it may be seen as a morning star very low in the east just before sunrise, but by month’s end it is too close to the sun for easy observation. Mars on the 15th is in R.A. 10h 16m, Decl. 12° 18' N., mag. +1.8, and transits at 8h 42m. In Leo, it rises about four hours before the sun. On the 10th it is only one degree north of Regulus. Jupiter on the 15th is in R.A. 8h 18m, Decl. 19° 54' N., mag. —1.7, and transits at 6h 44m. In Cancer, it rises at about midnight and is near the meridian at sunrise. For the configurations of Jupiter’s satellites see opposite page, and for their eclipses, etc., see p. 56. Saturn on the 15th is in R.A. 23h 43m, Decl. 4° 29' S., mag. +1.0, and transits at 22h 06m. In Pisces, it is risen by sunset and is visible until nearly sunrise. The earth is in the plane of the rings on the 29th. Uranus on the 15th is in R.A. 11h 32m, Decl. 3° 52' N., and transits at 9h 56m. Neptune on the 15th is in R.A. 15h 15m, Decl. 16° 19' S., and transits at 13h 39m. Pluto—For information in regard to this planet, see p. 31. Config. of Sun’s OCTOBER M in. Jupiter’s Selen. of Sat. Colong, E.S.T. Algol 16h 50m 0h U.T.

Venus greatest hel. lat. N ......

Pallas at opposition......

G Last Quarter...... Mercury at aphelion...... Jupiter 5° S. of m oon......

M ars 4° S. of m oon...... Uranus 4° S. of m oon...... Moon at perigee, 223,000 mi.... New M oon......

M ercury 2° S. of m oon...... Neptune 2° N. of moon......

Orionid meteors...... First Quarter...... Mercury 5° N. of Neptune......

Moon at apogee, 252,000 mi.... Saturn 2° N. of m oon...... Mercury greatest elong. E., 24°.. Jupiter in quadrature W...... Mercury greatest hel. lat. S...... Full Moon, Hunter’s Moon .. Penumbral eclipse of , p. 64.

Explanation of abbreviations on p. 4, of time on p. 10, of colongitude on p. 61. lOct 7, -7.04°; Oct. 19, +7.32°. bOct. 10, -6.72°; Oct. 23, +6.82°. Positions of the sun and planets are given for Oh Greenwich Ephemeris Time. The times of transit at the 75th meridian are given in local mean time, 0h at midnight; to change to Standard Time, see p. 10. Estimates of altitude are for an observer in latitude 45° N. The Sun—During November the sun’s R.A. increases from 14h 23m to 16h 26m and its Decl. changes from 14° 13' S. to 21° 42' S. The equation of time changes from + 16m 23s to +11m 21s. There is a total eclipse on the 12th, not visible generally in North America. For changes in the length of the day, see p. 18. The Moon—For its phases, perigee and apogee times and distances, and its conjunctions with the planets, see opposite page. Times of moonrise and moonset are given on p. 25. Mercury on the 1st is in R.A. 15h 54m, Decl. 23° 16' S., and on the 15th is in R.A 15h 42m, Decl. 20° 09' S., when it transits at 12h 01m. It is mostly too close to the sun for observation, inferior conjunction being on the 17th. However, by month’s end it is approaching greatest western elongation and may be seen as a morning star low in the south-east just before sunrise. Venus on the 1st is in R.A. 14h 16m, Decl. 12° 38' S., and on the 15th is in R.A. 15h 26m, Decl. 18° 12'S., when it has mag. —3.5, and transits at 11h 51m. It is in superior conjunction on the 8th, so that it is not easily observed during this month. Mars on the 15th is in R.A. 11h 24m, Decl. 5° 41' N., mag. +1.6, and transits at 7h 48m. In Leo, it rises about an hour after midnight and is approaching the meridian by sunrise. Jupiter on the 15th is in R.A. 8h 27m, Decl. 19° 30' N., mag. —1.9, and transits at 4h 51m. In Cancer, it rises about two hours before midnight and is past the meridian by sunrise. On the 21st it is stationary in right ascension and begins to retrograde, i.e. move westward, among the stars. For the configurations of Jupiter’s satellites see opposite page, and for their eclipses, etc., see p. 57. Saturn on the 15th is in R.A. 23h 38m, Decl. 4° 57' S., mag. +1.2, and transits at 19h 59m. In Pisces, it is well up at sunset and sets about two hours after midnight. On the 27th it is stationary in right ascension and resumes direct, or eastward, motion among the stars. Uranus on the 15th is in R.A. 11h 37m, Decl. 3° 16' N., and transits at 8h 00m. Neptune on the 15th is in R.A. 15h 20m, Decl. 16° 37' S., and transits at 11h 42m. Pluto—For information in regard to this planet, see p. 31.

Explanation of abbreviations on p. 4, of time on p. 10, of colongitude on p. 61. lNov. 3, -5.85°; Nov. 16, +6.31°; Nov. 30, -4.96°. bNov. 6, -6.79°; Nov. 19, +6.85°. Config. of Sun’s NOVEMBER Min. Jupiter’s Selen. of Sat. Colong. E.S.T. Algol 15h 15m 0h U.T.

Taurid meteors...... Jupiter 5° S. of moon...... Ceres stationary...... Last Quarter...... Mercury stationary...... Mars 3° S. of moon...... Uranus 4° S. of moon...... Venus in superior conjunction...

Moon at perigee, 225,800 mi. . . .

® New Moon...... Eclipse of , p. 64

Neptune in conjunction with sun

Leonid meteors...... Mercury at ascending node...... Mercury in inferior conjunction.

Mars greatest hel. lat. N...... First Quarter...... Mercury at perihelion...... Jupiter stationary...... Mars 1.0° N. of Uranus...... Saturn 2° N. of moon...... Moon at apogee, 251,500 mi. . . .

Mercury stationary...... Venus at descending node...... Saturn stationary...... Full Moon......

Pallas stationary...... Positions of the sun and planets are given for Oh Greenwich Ephemeris Time. The times of transit at the 75th meridian are given in local mean time, Oh at midnight; to change to Standard Time, see p. 10. Estimates of altitude are for an observer in latitude 45° N. The Sun—During December the sun’s R.A. increases from 16h 26m to 18h 43m and its Decl. changes from 21° 42' S. to 23° 05' S. The equation of time changes from +10m 59s to —2m 59s, being zero on the 25th.The solstice is on the 22nd at 2h 29m E.S.T. For changes in the length of the day, see p. 18. The Moon—For its phases, perigee and apogee times and distances, and its conjunctions with the planets, see opposite page. Times of moonrise and moonset are given on p. 25. Mercury on the 1st is in R.A. 15h 07m, Decl. 14° 54' S., and on the 15th is in R.A. 16h 12m, Decl. 19° 52' S., when it transits at 10h 39m. For a week or more at the beginning of the month it may be seen as a morning star low on the south-eastern horizon just before sunrise; greatest western elongation is on the 4th at which time it stands about 19 degrees above the south-eastern horizon at sunrise. Venus on the 1st is in R.A. 16h 49m, Decl. 22° 35' S., and on the 15th is in R.A. 18h 06m, Decl. 24° 06' S., when it has mag. —3.4, and transits at 12h 34m. It is an evening star but too close to the sun for easy observation. Mars on the 15th is in R.A. 12h 24m, Decl. 0° 3 2 'S., mag. +1.3, and transits at 6h 50m. In Virgo, it rises soon after midnight and is past the meridian at sunrise. Jupiter on the 15th is in R.A. 8h 24m, Decl. 19° 47' N., mag. —2.1, and transits at 2h 49m. In Cancer, it rises about three hours after sunset and is visible the rest of the night. For the configurations of Jupiter’s satellites see opposite page, and for their eclipses, etc., see p. 57. Saturn on the 15th is in R.A. 23h 39m, Decl. 4° 48' S., mag. +1.3, and transits at 18h 02m. In Pisces, it is nearing the meridian at sunset and sets at about midnight. The earth is in the plane of the rings on the 17-18th. Uranus on the 15th is in R.A. 11h 40m, Decl. 2° 58' N., and transits at 6h 05m. Neptune on the 15th is in R.A. 15h 24m, Decl. 16° 53' S., and transits at 9h 48m. Pluto—For information in regard to this planet, see p. 31. Config. of Sun’s DECEMBER Min. Jupiter’s Selen. of Sat. Colong. E.S.T. Algol 14h 30m 0h U.T.

Mercury greatest hel. lat. N . . . . Jupiter 5° S. of m oon......

Mercury greatest elong. W., 21°. G Last Quarter...... Mercury 0.6° N. of Neptune... . Uranus 4° S. of m oon...... M ars 2° S. of moon...... Moon at perigee, 229,200 mi. ...

Neptune 2° N. of moon...... Mercury 3° N. of moon...... New M oon...... Juno stationary...... Geminid meteors......

Saturn in quadrature E ...... Uranus in quadrature W......

Saturn 2° N. of m oon...... First Quarter...... Moon at apogee, 251,200 mi... .

Ursid meteors...... Solstice. Winter commences...... Ceres at opposition......

Mercury at descending node....

Mars at aphelion...... Full M oon......

Jupiter 5° S. of m oon...... Uranus stationary...... Pluto stationary......

Explanation of abbreviations on p. 4, of time on p. 10, of colongitude on p. 61. lDec. 14, +5.20°; Dec. 26, -5.37°. bDec. 3, —6.72°; Dec. 16, +6.71°; Dec. 30, 31, —6.55°. PHENOMENA OF JUPITER’S SATELLITES, E.S.T. 1956 E—eclipse, O—, T—transit, S—shadow, D—disappearance, R—reappearance, I— ingress, e—egress; E.S.T. (For other times see p. 10.) The phenomena are given for latitude 45° N., for Jupiter at least one hour above the horizon, and the sun at least one hour below the horizon. Note: Satellites move from east to west across the face of the planet, and from west to east behind it. Before opposition shadows fall to the west, and after opposition to the east. Thus eclipse phenomena occur on the east side from January to May, and on the west side from August to December.

SATURN’S SATELLITES, 1966 Greatest E. Mean Elongation Synodic Name E.S.T.* Period d h d h Mimas Sept. 19 13.8 0 22.6 Enceladus Sept. 18 21.8 1 8.9 Tethys Sept. 19 13.5 1 21.3 Dione Sept. 20 0.7 2 17.7 Rhea Sept. 18 13.3 4 12.5 Titan Sept. 23 13.6+ 15 23.3 Hyperion Sept. 28 8.5+ 21 07.6 Iapetus Sept. 9 4.9+ 79 22.1 Phoebe 523 15.6 *Near opposition of Saturn, 1966 Sept. 19. +See p. 58 for more information. E l o n g a t io n s a n d C onjunctions , E.S.T. 1966

T it a n

H y p e r io n

Ia p e t u s JUPITER’S BELTS AND ZONES

S. POLAR REGION S. S. TEMPERATE ZONE S. S. TEMPERATE BELT S. TEMPERATE ZONE S. TEMPERATE BELT S. TROPICAL ZONE S. EQUATORIAL BELT EQUATORIAL ZONE N. EQUATORIAL BELT N. TROPICAL ZONE N. TEMPERATE BELT N. TEMPERATE ZONE N. N. TEMPERATE BELT N. N. TEMPERATE ZONE N. POLAR REGION

Viewed through a telescope of 6-inch aperture or greater, Jupiter exhibits a variety of changing detail and colour in its cloudy atmosphere. Some features are of long duration, others are short-lived. The standard nomenclature of the belts and zones is given in the figure.

DIMENSIONS OF SATURN’S RINGS

At Mean Opposition Diameter Miles Distance Ratio " Outer Ring, A — outer 169,100 44.0 2.252 — inner 148,800 38.7 1.982 Inner Ring, B — outer 145,400 37.8 1.936 — inner 112,400 29.2 1.498 Dusky Ring — inner 92,700 24.1 1.236 Saturn — equatorial 75,100 19.5 1.000

During 1966 Saturn’s rings are in an almost edge-on position. The earth is in the plane of the rings three times, on Apr. 2, Oct. 29 and Dec. 17-18, when the rings will be completely invisible. Three passages through this plane will next occur in 1980. The major and minor axes of the outer edge of the outer ring have the following values during the year: Jan. 3, 37.21", 3.07"; Apr. 1, 35.55", 0.05" (northern face); July 14, 40.95", 2.13"; Oct. 26, 42.88", 0.05" (southern face); Dec. 17, 39.48", 0.01" (northern face); Dec. 29, 38.68", 0.19" (southern face). LONGITUDE OF JU PITER’S CENTRAL MERIDIAN

The table lists the longitude of the central meridian of the illuminated disk of Jupiter for given times daily during the period when the planet is favourably placed. System I applies to the regions between the middle of the North Equatorial Belt and the middle of the South Equatorial Belt; System II to the rest of the planet. Longitude increases hourly by 36.58° in System I and 36.26° in System II. Detailed ancillary tables may be found in “The Planet Jupiter” by B. M. Peek (Faber & Faber, 1958) on pages 274 and 275.

Dec. 1, 0h U. I .: System I: 315.3° ; System II: 336.4° The polar aurora is a self-luminous phenomenon of the upper atmosphere, which is seen most frequently in high latitudes, but is visible to at least a latitude of 14° in both hemispheres. Standard auroral forms and accepted abbreviations are shown in the figure. Regular observations, at the same times on successive nights are useful. Observations can be sent in Canada to Dr. Peter M. Millman, National Research Council, Ottawa, Ontario.

HA (HOMOGENEOUS ARC)

RA (RAYED ARC)

R (RAYS) PA (PULSATING PS (PULSATING ARC) SPOT)

F (FLAMES) G (GLOW) S (SPOT OR PATCH)

THE OBSERVATION OF THE MOON During 1966 the ascending node of the moon’s orbit moves from the constella­ tion Taurus into Aries ( from 63° to 43°). See p. 64 for occultations of stars. The sun's selenographic colongitude is essentially a convenient way of indicating the position of the sunrise terminator as it moves across the face of the moon. It provides an accurate method of recording the exact conditions of illumination (angle of illumination), and makes it possible to observe the moon under exactly the same lighting conditions at a later date. The sun’s selenographic colongitude is numerically equal to the selenographic longitude of the sunrise terminator reckoned eastward from the mean centre of the disk. Its value increases at the rate of nearly 12.2° per day or about ½° per hour; it is approximately 270°, 0°, 90° and 180° at New Moon, First Quarter, Full Moon and Last Quarter respectively. (See the tabulated values for 0h U.T. starting on p. 33.) Sunrise will occur at a given point east of the central meridian of the moon when the sun’s selenographic colongitude is equal to the eastern selenographic longitude of the point; at a point west of the central meridian when the sun’s selenographic colongitude is equal to 360° minus the western selenographic longitude of the point. The longitude of the sunset terminator differs by 180° from that of the sunrise terminator. The sun’s selenographic latitude varies between + 1½° and — 1½° during the year. By the moon’s libration is meant the shifting, or rather apparent shifting, of the visible disk. Sometimes the observer sees features farther around the eastern or the western limb (libration in longitude), or the northern or southern limb (libration in latitude). The quantities called the earth’s selenographic longitude and latitude are a convenient way of indicating the two librations. When the libration in longitude, that is the selenographic longitude of the earth, is positive, the mean central point of the disk of the moon is displaced eastward on the , exposing to view a region on the west limb. When the libration in latitude, or the selenographic latitude of the earth, is positive, the mean central point of the disk of the moon is displaced towards the south, and a region on the north limb is exposed to view. In the Astronomical Phenomena Month by Month the dates of the greatest positive and negative values of the libration in longitude are indicated by l in the column headed "Sun’s Selenographic Colongitude,” and their values are given in the footnotes. Similarly the extreme values of the libration in latitude are indicated by b. Two areas suspected of showing changes are Alphonsus and Aristarchus.

MAP OF THE MOON

CL AVI US

THEOPHILUS MARE NUBIUM MARE AND NECTARIS STRAIGH T WALL

PETAVIUS MARE h u m o r u m MARE FOECUNDITATIS

GRIMALDI LANGRENUS

TARUNTIUS KEPLER PLINIUS

MARE CRISIUM COPERNICUS

MACROBIUS POSDONIUS ARISTARCHUS

ATLAS ERATOSTHENES

ENDYMION ARCHIMEDES MANILIUS ARISTILLUS STRAIGHT RANGE CAUCASUS MTS PLATO ALPS MTS ALPINE VALLEY APEN N IN E MTS South appears at the top. EPHEMERIS FOR THE PHYSICAL OBSERVATIONS OF THE SUN, 1966 For 0h U.T.

P—The position angle of the axis of rotation, measured eastward from the north point of the disk. B0—The heliographic latitude of the centre of the disk. L0—The heliographic longitude of the centre of the disk, from Carrington’s solar meridian.

Carrington’s Rotation Numbers—Greenwich Date of Commencement of Synodic Rotations, 1966 No. Commences No. Commences No. Commence 1503 Jan. 9.40 1508 May 25.87 1513 Oct. 9.02 1504 Feb. 5.74 1509 June 22.07 1514 Nov. 5.32 1505 Mar. 5.08 1510 July 19.27 1515 Dec. 2.63 1506 Apr. 1.38 1511 Aug. 15.50 1516 Dec. 29.95 1507 Apr. 28.65 1512 Sept. 11.75 In 1966 there will be four eclipses, two of the sun and two of the moon. Of these only the penumbral eclipse of the moon of the night of October 28-29 will be visible generally in North America.

1. A penumbral eclipse of the moon on May 4, not visible at all in North America.

2. An annular eclipse of the sun on May 20, visible in the South Atlantic, Africa and Asia but not at all in North America.

3. A penumbral eclipse of the moon on the night of October 28-29 “visible” (though penumbral eclipses are barely detectable) generally in North America.

Moon enters penumbra...October 29, 2h 53m E.S.T. Middle of eclipse...... 5h 12m E.S.T. Moon leaves penumbra...... 7h 31m E.S.T.

4. A total eclipse of the sun on November 12, visible in South America and across the South Atlantic, visible as a partial eclipse in Central America, Mexico and in the American States near the Gulf of Mexico.

LUNAR OCCULTATIONS

When the moon passes between the observer and a star that star is said to be occulted by the moon and the phenomenon is known as a lunar occultation. The passage of the star behind the east limb of the moon is called the immersion and its re-appearance from behind the west limb the emersion. As in the case of eclipses, the times of immersion and emersion and the duration of the occultation are different for different places on the earth’s surface. The tables given below, are adapted from data supplied by the British Nautical Almanac Office and give the times of immersion or emersion or both for occultations visible from six stations distributed across Canada. Stars of magnitude 7.5 or brighter are included as well as daytime occultations of very bright stars and planets. Since an occul­ tation at the bright limb of the moon is difficult to observe the predictions are limited to phenomena occurring at the dark limb. The terms a and b are for determining corrections to the times of the phenomena for stations within 300 miles of the standard stations. Thus if λ0, φ0, be the longitude and latitude of the standard station and λ, φ, the longitude and latitude of the neighbouring station then for the neighbouring station we have: Standard Time of phenomenon = Standard Time of phenomenon at the standard station + a (λ— λ0)+ b(φ — φ0) where λ —λ0 and φ — φ0 are expressed in degrees. The quantity P is the position angle of the point of contact on the moon’s disk reckoned from the north point towards the east. The co-ordinates of the standard stations are: Halifax, λ0 63° 36.0', φ0+44° 38.0'; Montreal, λ0 73° 34.7', φ0+45° 30.3'; Toronto, λ0 79° 23.9', φ0+43° 39.8'; Winnipeg, λ0 97° 06.0', φ0+ 49° 55.0; Edmonton, λ0113°05', φ0+53°32'; Vancouver, λ0 123° 06', φ0+49° 30'.

LUNAR OCCULTATIONS VISIBLE AT HALIFAX AND MONTREAL, 1906 LUNAR OCCULTATIONS VISIBLE AT TORONTO AND WINNIPEG, 1966 LUNAR OCCULTATIONS VISIBLE AT EDMONTON AND VANCOUVER, 1966

PLANETARY APPULSES AND OCCULTATIONS

The close approach of a planet to a star is of interest to observers. Surprisingly few observable appulses of planets and stars of 9th magnitude or brighter occur during a year. An even rarer occurrence is the observable occultation of a star by a planet. No planetary appulses or occultations are observable from Canada during 1966, according to Mr. Gordon E. Taylor of the British Astronomical Association.

Do you know... ■ That the University of Toronto Press is one of only four printing plants in the world using the four-line system of typesetting mathematical formulas mechanically? ■ That this system has been developed to its highest degree of mechanization and efficiency right here at University of Toronto Press? ■ That printing experts and scholars from the United States, Great Britain, and other parts of the world regularly visit our plant to see this system in operation? ■ That this research and experimentation has been made possible only by the co-operation of Canadian scholars, scientific societies and non-profit scientific journals? for mathematical and scientific printing UNIVERSITY OF TORONTO PRESS

OPPOSITION EPHEMERIDES OF THE BRIGHTEST ASTEROIDS, 1966

The asteroids are many small objects revolving around the sun mainly between the orbits of Mars and Jupiter. The largest, Ceres, is only 480 miles in diameter. Vesta, though half the diameter of Ceres, is brighter. The next brightest asteroids, Juno and Pallas, are 120 and 300 miles in diameter, respectively. Unlike the planets the asteroids move in orbits which are appreciably elongated. Thus the distance of an from the earth (and consequently its magnitude) varies greatly at different oppositions. Ephemerides for the four brightest asteroids are given when the asteroids are near opposition, along with maps for Ceres and Vesta. Since Vesta was at opposi­ tion near the end of 1965, the map for this opposition is repeated. Right ascensions and are for Oh E.T. and equinox of 1950.0. P a l l a s (No. 2) C e r e s (N o . 1) Opp. Oct. 5 in Cet Mag 8.1 Opp. Dec. 22 in Gem Mag. 6. 6 h m h m Sept. 10 1 26.6 - 6 ° 12 ' Dec. 2 6 18.5 +24°44' 15 1 24.6 - 7 33 7 6 14.4 +25 06 20 1 22.0 - 8 55 12 6 09.8 +25 29 25 1 19.0 -1 0 19 17 6 04.7 +25 51 30 1 15.7 -1 1 42 22 5 59.5 +26 12 Oct. 5 1 12.0 -1 3 03 27 5 54.2 +26 31 10 1 08.2 -14 21 Jan. 1 5 49.1 +26 49 15 1 04.2 -1 5 34 20 1 00.3 -1 6 41 25 0 56.6 -17 41

V e s ta (N o. 4) Opp. 1965 Dec. 28 Mag. 6. 6 1966 h m Jan. 1 6 22.7 +22°00' 6 6 17.2 +22 17 11 6 11.9 +22 34 16 6 07.0 +22 49 METEORS, FIREBALLS AND METEORITES

B y P e t e r M . M il l m a n Meteoroids are small solid particles moving in orbits about the sun. On entering the earth’s atmosphere at velocities ranging from 10 to 45 miles per second they become luminous and appear as meteors or fireballs and, if large enough to avoid complete vapourization, in rare cases they may fall to the earth as meteorites. Meteors are visible on any night of the year. At certain times of the year the earth encounters large numbers of meteors all moving together along the same orbit. Such a group is known as a meteor shower and the accompanying list gives the more important showers visible in 1966. The Leonid shower is increasing in strength and will be of particular interest. The Perseid and the Geminid showers are the two best showers for the amateur. On the average an observer sees 7 meteors per hour which are not associated with any recognized shower. These have been included in the hourly rates listed in the table. The radiant is the position among the stars from which the meteors of a given shower seem to radiate. The appearance of any very bright fireball should be reported immediately to the nearest astronomical group or other organi­ zation concerned with the collection of such information. Where no local organiza­ tion exists, reports should be sent to Meteor Centre, National Research Council, Ottawa 2, Ontario. Free fireball report forms and instructions for their use, printed in either French or English, may be secured at the above address. If sounds are heard accompanying a bright fireball there is a possibility that a meteo­ rite may have fallen. Astronomers must rely on observations made by the general public to track down such an object. The velocities of shower meteors in miles per second are: Quadrantids, 25; Lyrids, 30; η Aquarids, 40; δ Aquarids, 25; Perseids, 37; Orionids, 41; Taurids, 17; Leonids, 45; Geminids, 22; Ursids, 21.

M e t e o r S h o w e r s F o r 1966

Shower Maximum Radiant Single Norm al Ob­ D uration Position Daily server to ¼ at Max. Motion Hourly strength Shower D ate E.S.T. Moon R.A. Dec. R.A. Dec. Rate Vel. of M ax. h m O m ° m i./sec. days Quadrantids Jan. 3 13h F.M . 15 28 + 50 —— 40 25 0 .6 Lyrids Apr. 22 06 N.M . 18 16 + 34 + 4 .4 0 .0 15 30 2.3 η Aquarids May 5 06 F.M . 22 24 00 + 3 .6 +0.4 20 40 1.8 δ Aquarids July 29 — F.M. 22 36 - 1 7 + 3 .4 + 0 .1 7 20 25 20 Perseids Aug. 12 09 L.Q. 03 04 +58 + 5 .4 + 0 .1 2 50 37 5 .0 Orionids Oct. 20 21 F.Q. 06 20 +15 + 4 .9 + 0 .1 3 25 41 8 Taurids Nov. 5 — L.Q. 03 32 +14 + 2 .7 + 0 .1 3 15 17 (30) Leonids Nov. 16 20 F.Q. 10 08 + 22 + 2 .8 - 0 .4 2 25 45 4 Geminids Dec. 13 14 N.M. 07 32 +32 + 4 .2 - 0 .0 7 50 22 6 .0 Ursids Dec. 22 19 F.Q. 14 28 +76 15 21 2 .2

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on the front campus UNIVERSITY OF TORONTO hours: 9 - 5 TABLE OF PRECESSION FOR 50 YEARS FINDING LIST OF NAMED STARS

Acamar 02 Fomalhaut 22 Achernar 01 Gacrux 12 Acrux 12 Gienah 12 Adhara 06 Hadar 14 Al Na’ir 22 Hamal 02 Albireo 19 Kaus Australis 18 Alcyone 03 Kochab 14 04 Markab 23 Alderamin 21 Megrez 12 Algenib 00 Merikar 03 Algol 03 Menkent 14 Alioth 12 Merak 10 Alkaid 13 Miaplacidus 09 Almach 02 Mira 02 Alnilam 05 Mirach 01 Alphard 09 Mirfak 03 Alphecca 15 Mizar 13 Alpheratz 00 Nunki 18 Altair 19 Peacock 20 Ankaa 00 Phecda 11

Antares 16 Polaris 01 Arcturus 14 Pollux 07 Atria 16 Procyon 07 Avior 08 Ras-Algethi 17 Bellatrix 05 Rasalhague 17 05 Regulus 10 Canopus 06 Rigel 05 Capella 05 Rigil Kentaurus 14 Caph 00 Sabik 17 07 Scheat 23

Deneb 20 Schedar 00 Denebola 11 Shaula 17 Diphda 00 Sirius 06 Dubhe 11 13 Elnath 05 Suhail 09 Eltanin 17 Vega 18 Enif 21 Zubenelgenubi 14

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MANUFACTURERS OF TV PICTURE TUBES AND CATHODE-RAY TUBES THE BRIGHTEST STARS By Donald A. MacRae The 286 stars brighter than 3.55. Star. If the star is a visual double the letter A indicates that the data are for the brighter component. The brightness and separation of the second component B are given in the last column. Sometimes the double is too close to be conveniently resolved and the data refer to the combined light, AB; in interpreting such data the magnitudes of the two components must be considered. Visual Magnitude ( V). These magnitudes are based on photoelectric obser­ vations, with a few exceptions, which have been adjusted to match the yellow colour-sensitivity of the eye. The photometric system is that of Johnson and Morgan in A p. J., vol. 117, p. 313, 1953. It is as likely as not that the true magnitude is within 0.03 mag. of the quoted figure, on the average. Variable stars are indicated with a “v". The type of variability, range, R, in magnitudes, and period in days are given. Colour index (B-V). The blue magnitude, B, is the brightness of a star as observed photoelectrically through a blue filter. The difference B-V is therefore a measure of the colour of a star. The table reveals a close relaton between B - V and spectral type. Some of the stars are slightly reddened by interstellar dust. The probable error of a value of B-V is only 0.01 or 0.02 mag. Type. The customary spectral (temperature) classification is given first. The Roman numerals are indicators of luminosity class. They are to be in­ terpreted as follows: Ia—most luminous supergiants; Ib—less luminous super­ giants; II—bright giants; III—normal giants; IV—subgiants; V—main sequence stars. Intermediate classes are sometimes used, e.g. Iab. Approximate absolute magnitudes can be assigned to the various spectral and luminosity class combina­ tions. Other symbols used in this column are: p—a peculiarity; e—emission lines; v—the spectrum is variable; m—lines due to metallic elements are ab­ normally strong; f—the O-type spectrum has several broad emission lines; n or nn—unusually wide or diffuse lines. A composite spectrum, e.g. M 1 Ib+B , shows up when a star is composed of two nearly equal but unresolved compo­ nents. In the far southern sky, spectral types in italics were provided through the kindness of Prof. R. v. d. R. Woolley, Australian Commonwealth Observa­ tory. Types in parentheses are less accurately defined (g—giant, d—dwarf, c-exceptionally high luminosity). All other types were very kindly provided especially for this table by Dr. W. W. Morgan, Yerkes Observatory. Parallax (π). From “General Catalogue of Trigonometric Stellar Paral­ laxes” by Louise F. Jenkins, Yale Univ. Obs., 1952. Absolute visual magnitude (Mv), and distance in light-years (D). If π is greater than 0.030" the distance corresponds to this trigonometric parallax and the absolute magnitude was computed from the formula Mv = F + 5 + 5 log π. Otherwise a generally more accurate absolute magnitude was obtained from the luminosity class. In this case the formula was used to compute π and the distance corresponds to this “spectroscopic” parallax. The formula is an expression of the inverse square law for decrease in light intensity with increasing distance. The effect of absorption of light by interstellar dust was neglected, except for three stars, ζ Per, σ Sco and ζ Oph, which are significantly reddened and would therefore be about a magnitude brighter if they were in the clear. Annual proper motion (µ), and radial velocity (R). From “General Catalogue of Stellar Radial Velocities” by R. E. Wilson, Carnegie Inst. Pub. 601, 1953. Italics indicate an average value of a variable radial velocity. The star names are given for all the officially designated navigation stars and a few others. Throughout the table, a colon (:) indicates an uncertainty. We are indebted to Dr. Daniel L. Harris, Yerkes Observatory, particularly for his compilation of the photometric data from numerous sources. Sun Alpheratz Caph Algenib Ankaa

Schedar Diphda

Mirach

Achernar Polaris Almach Hamal Mira Acamar Menkar

Algol Mirfak Al cyone

Aldebaran

a UMi, Polaris: R.A. 2 h 00.2 m; Dec. +89° 06' (1966). Rigel Capella Bellatrix Elnath

Alnilam

Betelgeuse

Canopus Sirius

Adhara

Castor Procyon Pollux

Avior Suhail

Miaplacidus

Alphard

Regulus

Merak Dubhe

Denebola Phecda

Megrez Gienah Acrux

Gacrux

Beta Crucis Alioth

Mizar Spica

Alkaid Hadar Menkent Arcturus

Rigil Kentaurus

Zubenelgenubi Kochab

Alphecca

Atria

Sabik

Ras-Algethi

Shaula Rasalhague Eltanin

Kaus Australis Vega

Nunki

Albireo

Altair Peacock Deneb

Alderamin

Enif

Al Na'ir

Fomalhaut Scheat Markab DOUBLE AND MULTIPLE STARS

By C h a r l e s E. W o r l e y

Many stars can be separated into two or more components by use of a telescope. The larger the aperture of the telescope, the closer the stars which can be separated under good seeing conditions. With telescopes of moderate size and average optical quality, and for stars which are not unduly faint or of large magnitude difference, the minimum angular separation is given by 4.6/D, where D is the diameter of the telescope’s objective in inches. The following lists contain some interesting examples of double stars. The first list presents pairs whose orbital motions are very slow. Consequently, their angular separations remain relatively fixed and these pairs are suitable for testing the performance of small telescopes. In the second list are pairs of more general interest, including a number of binaries of short period for which the position angles and separations are changing rapidly. In both lists the columns give, successively; the star designation in two forms; its right ascension and declination for 1970; the combined visual magnitude of the pair and the individual magnitudes; the apparent separation and position angle for 1966. 0; and the period, if known. Many of the components are themselves very close visual or spectroscopic binaries. (Other double stars appear in the table of The Brightest Stars, p. 74, and of The Nearest Stars, p. 86.)

*There is a marked colour difference between the components. THE NEAREST STARS

B y R. M. Petrie and Jean K. M c D o n a ld

Perhaps the most difficult problem in observational astronomy is the deter­ mination of the distances to the stars. The reason, of course, is that the distances are so enormous as to require the measurement of vanishingly small angular displacements. As the earth goes in its orbit around the sun the stars show a small change in their positions and it is this small apparent movement which is called the annual parallax. If we can measure the parallax we can at once calculate the distance to the star concerned. Astronomers speak of stellar distances in terms of light-years or, alternatively, parsecs. A light-year is the distance light travels in one year with its speed of 186,000 miles per second. If we know the parallax in seconds of arc we obtain the distance in light-years by dividing 3.26 by the parallax. Thus the star Sirius, which has an annual parallax of 0."375, is 8.7 light-years distant. The reciprocal of the parallax gives the distance in parsecs; Sirius is 2.7 parsecs from the sun. The apparent motion, per year, of a star across the sky, called proper motion, is a good indication of a star’s distance. Obviously, the nearer stars will appear to move more rapidly than their more distant fellows and this fact has many times been instrumental in the discovery of nearby stars. The table accompanying this note lists, in order of distance, all known stars within sixteen light-years. Including the sun it contains fifty-five stars, but it does not contain the unseen companions of double and multiple stars entered in the table. The table is taken from a paper by Professor van de Kamp, pub­ lished in 1953. In addition to the name and position for each star, the table gives spectral type, Sp.; parallax, π; distance in light-years, D; proper motion in second of arc per year, µ; total velocity with respect to the sun in km./sec., W; apparent visual magnitude, m; and finally, luminosity in terms of the sun, L. In column four, wd indicates a white dwarf, and e indicates an emission-line star. The stars within sixteen light-years form an important astronomical table because the annual parallaxes are large enough to be well determined. This means that we have accurate knowledge of the distances, speeds, and lumino­ sities of these stars. Furthermore this sample is probably quite representative of the stellar population in our part of the galaxy, and as such is well worth our study. It is interesting to note that most of the stars are cool red dwarfs, of type M. This must be the most populous of all the stellar varieties. Only ten of these nearby stars are bright enough to be seen with the unaided eye (magnitude less than five). Only three stars, Sirius, Altair, and Procyon, are brighter than the sun while the great majority are exceedingly faint. Not one giant star is contained in the list nor is there a B-type star. This is a consequence of the extreme rarity of very hot and very bright stars. One may conclude that stars brighter than the sun are very scarce. Another striking fact is the prevalence of double and multiple stars, there being sixteen such systems if we count unseen components. Obviously double and multiple stars are quite common in the stellar population, and must be explained by any acceptable theory of stellar formation and evolution. *Star has an unseen component.

Study the Stars with Binoculars and Telescopes from EATON’S OF CANADA (Business Not Solicited in the U.S.A.) Maps of the fields of four bright variable stars are given below. In each case the magnitudes of several suitable comparison stars are given. Note that the decimal points are omitted: a star 36 is of mag. 3.6. Use two comparison stars, one brighter and one fainter than the variable, and estimate the brightness of the variable in terms of these two stars. Record the date and time of observation. When a number of observations have been made, a graph may be plotted showing the magnitude estimate as ordinates against the date (days and tenths of a day) as abscissae. Each type of variable has a distinctive shape of light curve. In the tables the first column, the Harvard designation of the star, gives the 1900 position: the first four figures give the hours and minutes of R.A., the last two figures give the Dec. in degrees, italicised for southern declinations. The column headed M ax. gives the mean maximum magnitude. The Period is in days. The Epoch gives the predicted date of the earliest maximum occurring this year; by adding the period to this epoch other dates of maximum may be found. The list of long-period variables has been prepared by the American Association of Variable Star Observers and includes the variables with maxima brighter than mag. 8.0, and north of Dec. —20°. These variables may reach maximum two or three weeks before or after the listed epoch and may remain at maximum for several weeks. The second table contains stars which are repre­ sentative of other types of variable. The data are taken from “The General Catalogue of Variable Stars” by Kukarkin and Parenago and for eclipsing binaries from Rocznik Astronomiczny Obserwatorium Krakowskiego, 1965, International Supplement. OTHER TYPES OF VARIABLE STARS

*Minimum The star clusters for this observing list have been selected to include the more conspicuous members of the two main classes—open clusters and globular clusters. Most of the data are from Shapley’s Star Clusters and from Trump- ler’s catalogue in Lick Bulletin No. 420. In the following table N.G.C. indicates the serial number of the cluster in the New General Catalogue of Clusters and Nebulae; M, its number in Messier’s catalogue; Con., the constellation in which it is located; a and δ, its right ascension and declination; Cl., the kind of cluster, Op for open or galactic and Gl for globular; Diam., the apparent diameter in minutes of arc; Mag. B.S., the magnitude of the fifth brightest star in the case of open clusters, the mean of the 25 brightest for globulars; No., the number of stars in the open clusters down to the limiting magnitudes of the photographs on which the particular clusters were studied; Int. mag., the total apparent magnitude of the globular clusters; and Dist., the distance in light years. GALACTIC NEBULAE The galactic nebulae here listed have been selected to include the most readily observable representatives of planetary nebulae such as the Ring Nebula in Lyra, diffuse bright nebulae like the Orion nebula and dark absorbing nebulo­ sities such as the Coal Sack. These objects are all located in our own galactic system. The first five columns give the identification and position as in the table of clusters. In the Cl column is given the classification of the nebula, planetary nebulae being listed as Pl, diffuse nebulae as Dif, and dark nebulae as Drk. Size indicates approximately the greatest apparent diameter in minutes of arc; and m n is the magnitude of the planetary nebula and m * is the magnitude of its central star. The distance is given in light years, and the name of the nebula is added for the better known objects. EXTERNAL GALAXIES Among the hundreds of thousands of systems far beyond our own galaxy relatively few are readily seen in small telescopes. The following list contains a selection of the closer brighter objects of this kind. The first five columns give the catalogue numbers, constellation and position on the celestial sphere. In the column Cl, E indicates an elliptical nebula, I an irregular object, and Sa, Sb, Sc spiral nebulae, in which the spiral arms become increasingly dominant com­ pared with the nucleus as we pass from a to c. The remaining columns give the apparent magnitude of the nebula, its distance in light years and the radial velocity in kilometers per second. As these objects have been selected on the basis of ease of observation, the faint, very distant objects which have spec­ tacularly large red shifts, corresponding to large velocities of recession, are not included. RADIO SOURCES

B y J o h n G a l t

This table lists most of the strongest sources of radio emission as well as a representative number of sources with interesting properties. Although most of these have been identified with optical objects, it should be remembered that many of the weaker sources remain unidentified. The flux, which is a measure of the intensity of the source, is given in units of 10-26 watts/metre2/cycle per second at a frequency of 960 Mc./sec. or a wave-length of 31 cm. The relative intensities of these sources can be quite different at different frequencies. In particular Jupiter is a very strong emitter at lower frequencies. The distances are derived, in general, from measurements in the optical region. Many extra-galactic sources are double and this is indicated in the column ‘‘Approximate Radio Size” by noting the size of each individual emitting region followed by their separation, s. The above map represents the evening sky at Midnight...... Feb. 6 11 p.m...... “ 21 10 “ ...... Mar. 7 9 “ ...... “ 22 8 “ ...... Apr. 6 7 " ...... “ 21 The centre of the map is the zenith, the circumference the horizon. To identify the stars hold the map so that the part of the horizon you are facing is down. A set of four 8-inch horizon maps may be obtained by writing to the National Office. The above map represents the evening sky at Midnight...... May 8 11 p.m...... " 24 10 " ...... June 7 9 " ...... " 22 8 " ...... July 6 The centre of the map is the zenith, the circumference the horizon. To identify the stars hold the map so that the part of the horizon you are facing is down. The above map represents the evening sky at Midnight...... Aug. 5 11 p.m...... " 21 10 . Sept. 7 9 . " 23 8 .Oct. 10 7 . " 26 6 . Nov. 6 5 . " 21 The centre of the map is the zenith, the circumference the horizon. To identify the stars hold the map so that the part of the horizon you are facing is down. The above map represents the evening sky at Midnight...... Nov. 6 11 p.m...... 21 10 . Dec. 6 9 21 8 .Jan. 5 7 20 6 .Feb. 6 The centre of the map is the zenith, the circumference the horizon. To identify the stars hold the map so that the part of the horizon you are facing is down. Keep Informed on Astronomy and Space

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STAR ATLASES We publish the largest selection of sky atlases to fit your observing needs. Whether you’re a beginning amateur or an advanced astronomer, write for our free 24-page booklet “C” describing these celestial maps and other Sky Publications. Please enclose check or money order payable to Sky Publishing Corporation 02138 A LEADER IN QUALITY OPTICS

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New features have been added to UNITRON'S If this sounds like what you have been waiting popular, portable 2.4" Equatorial. Setting circles for in a telescope, we have some good news are now standard equipment. An optional syn­ indeed. These new features—the circles and chronous motor clock drive may be obtained supplementary slow motion—are included at no with the telescope or added later. In addition extra charge. The price of $225 includes view­ to the hand drive, a supplementary R.A. slow finder, 5 eyepieces, UNIHEX Rotary Eyepiece motion has been included to facilitate changes Selector, Achromatic Amplifier, sunglass, cabi­ in this coordinate without the need to stop or nets, etc. The accessory drive is priced at $50 disengage the motor. extra. Write for complete details.

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INSTRUMENT COMPANY - TELESCOPE SALES DIV. 66 NEEDHAM ST., NEWTON HIGHLANDS, MASS. 02161 NEW UNITRON CLOCK DRIVE MODELS Synchronous motor clock drives are now avail­ Each UNITRON comes complete with an assort­ able for all UNITRON Equatorial Models. The ment of eyepieces and accessories as standard new drive, pictured on the back cover of this equipment. In addition, our barlow-type Achro­ issue, is priced at $50 for the 2.4" and at $60 matic Amplifier is now included at no extra for the 3" and 4 " models. The 4 " refractors are cost. A proven reputation for optical and also available with our popular weight-driven mechanical quality plus unique features and clock drive which operates independently of a extra value make a UNITRON Refractor the source of electricity. logical telescope for you to choose.

1.6" ALTAZIMUTH $75 with eyepieces for 78x, 56x, 39x 2.4" ALTAZIMUTH $125 with eyepieces for 100x, 72x, 50x, 35x 2.4" EQUATORIAL $225 with eyepieces for 129x, 100x, 72x, 50x, 35x 3" ALTAZIMUTH $265 with eyepieces for 171x, 131x, 96x, 67x, 48x 3" EQUATORIAL $435 This valuable 38-page book with eyepieces for 200x, 131x, 96x, 67x, 48x is yours for the asking! 3" PHOTO-EQUATORIAL $550 with eyepieces for 200x, 171x, 131x, 96x, With artificial satellites already launched and space travel almost a reality, astronomy has become today’s 67x, 48x fastest growing hobby. Exploring the skies with a tele­ 4" ALTAZIMUTH $465 scope is a relaxing diversion for father and son alike. with eyepieces for 250x, 214x, 167x, 120x, UNITRON’s handbook contains full-page illustrated 83x, 60x articles on astronomy, observing, telescopes and acces­ sories. It is of interest to both beginners and advanced 4" EQUATORIAL $785 amateurs. with eyepieces for 250x, 214x, 167x, 120x, Contents include— 83x, 60x, 38x Observing the sun, 4" PHOTO-EQUATORIAL $890 moon, planets and with eyepieces for 250x, 214x, 167x, 120x, wonders of the sky 83x, 60x, 38x Constellation map Hints for observers 4" EQUITORIAL with weight-driven $985 Glossary of telescope terms clock drive, eyepieces as above How to choose a telescope 4" EQUATORIAL with weight-driven $1075 Amateur clubs and research clock drive, metal pier, eyepieces as above programs 4" PHOTO-EQUATORIAL with weight- $1175 driven clock drive and ASTRO-CAMERA, with eyepieces for 250x, 214x, 167x, 120x, 83x, 60x, 38x, 25x

4" PHOTO-EQUATORIAL with weight- $1280 66 NEEDHAM STREET, NEWTON HIGHLANDS, MASS. 02161 driven clock drive, pier, ASTRO-CAMERA, eyepieces for 375x, 300x, 250x, 214x, 167x, 120x, 83x, 60x, 38x, 25x Please rush to me, free of charge, UNITRON’s new Observer's uide and Telescope Catalog. 5" PHOTO-EQUATORIAL with clock $2275 NameG drive and ASTRO-CAMERA with eyepieces for Street 500x, 400x, 333x, 286x, 222x, 160x, 111x, C i t y S t a t e 80x, 50x, 33x 6" EQUATORIAL with clock drive, $5125 pier, 2.4" view finder, with 10 eyepieces HOW TO ORDER 6" PHOTO-EQUATORIAL as above but $5660 Send check or money order in full. Shipments with 4 " guide telescope, illuminated diagonal, made express collect. Send 20% deposit for UNIBALANCE, ASTRO-CAMERA Model 330 C.O.D. shipment. UNITRON instruments are 6" PHOTO-EQUATORIAL as above with $6075 fully guaranteed for quality workmanship, and addition of 3" Astrographic Camera Model 80 performance.

INSTRUMENT COMPANY - TELESCOPE SALES DIV. 66 NEEDHAM ST., NEWTON HIGHLANDS, MASS. 02161 W ITH STARS IN T H E I R EYES... Planners responsible for the planetaria being built in Calgary and Toronto have selected CARL ZEISS/JENA V.E.B. equipment “of the highest order”. These projection instruments are the most advanced of their kind in the world. Each has 120 separate projectors linked in such a way that they can show, on the giant domelike screen, the night sky in all its infinite variety . . . as it would be seen at any time in the past, or as it will be seen at any time in the future . . . from any point on earth. The dumbbell-shaped machines will stand 16' high and weigh close to 2½ tons. After long and thorough investigation of all possible sources, CARL ZEISS/JENA was actually a logical choice to supply this optical equipment. Here is the birthplace of modern optics and here are the acknowledged leaders in this specialized field. The CARL ZEISS/JENA instruments being built for Canada will incorporate new design features which outstrip any other now available. 1967 promises to be a banner year for star-gazers all over the country, who look forward to the opening of these planetaria with stars in their eyes. JENA SCIENTIFIC 23 Railside Rd., DON MILLS, Ont., Tel.: 447-4761 INSTRUMENTS LTD. 4040 Courtrai St., MONTREAL, Quebec, Tel.: 342-0251 UNUSUAL OPTICAL BUYS See the Stars, Moon, Close Up! Make Your Own Powerful Astronomical 3" REFLECTING TELESCOPE Telescope 60 to 180 Power—An Unusual Buy! GRIND YOUR OWN ASTRONOMICAL MIRROR Famous Mt. Palomar Type Kits contain mirror You’ll see the Rings of blank, tool, abra­ Saturn, the fascinating sives, diagonal mir­ planet Mars, huge craters ror and eyepiece on the Moon, Star Clusters, lenses. You can of Jupiter in detail. build instruments ranging in value from $75.00 Aluminized and overcoated to hundreds of dollars. 3" diameter high-speed Mirror Stock # Dio. Thickness Price f / 10 mirror. Equatorial ¾ " mount with lock on both axes. An Optical 7 0 ,0 0 3 -V 4 ¼" $ 7 .50 ppd. Finder Telescope is also included. Sturdy, 7 0 ,0 0 4 -V 6 " 1 " 11.95 ppd. hardwood, portable tripod. Free with scope 7 0 ,0 0 5 -V 8 " 1 ⅜ " 19.50 ppd. 7 0 ,0 0 6 -V 10" 1¾ " 30.75 } f.o.b. —valuable star chart and 272 page “ Astronomy 7 0 ,0 0 7 -V 12½ " 59.95 } Barrington Book”. Order by Stock No. Send check or 2⅛" M. O.—Money-back guarantee! NEW EDMUND STAR FINDER Stock No. 85,050-V $29.95 Postpaid With this precision-made metal 4¼ " Astronomical Reflector Telescope instrument, any observer can Stock No. 85.105-V $79.50 F.O.B. quickly locate and identify any charted star visible to the naked THE PLANETARIUM PORTRAYS THE eye. No optics are involved. FASCINATING STORY Overall size is 8" by 4" wide, OF EARTH IN ACTION 7¼ " deep. The finder is de­ signed for use on any photo­ Here is the story of cosmic graphic tripod or simple mount. motions—how the moon re­ (Suggestions for mounting are given.) Full volves around the earth, directions included. and the earth around the Stock # 70,501-V ...... $9.00 ppd. sun, with our planet rotat­ ing simultaneously. With this instrument,, the observer sees a three- NEW ZOOM dimensional moving demonstration of how TELESCOPE EYEPIECE seasons, day and night, and moon phases oc- cur. This handsome gear-and-chain-driven Exciting new eyepiece provides greater speed unit is supported by a smartly finished wood and versatility for your telescope. Does work base. The sun is 6" high, base 8" wide; arc is of many and stays sharp at all powers. Magni­ 18" long. A completely illustrated, delightfully fication depends on your telescope—typically informative handbook included. 50x to 120x. Precision construction, standard 1¼" O.D. Fully orthoscopic, coated lenses, Stock No. 70,415-V $29.95 ppd. focal length 8.4 mm. to 21 mm. Use of Barlow increases powers by 2 to 3 times. Pack & Pinion Eyepiece Mounts Stock No. 60,362-V ...... $26.50 ppd. Real rack-and-pinion focusing with variable tension adjust­ Remove, Replace Retaining Rings Quickly with ment; tube accommodates stan­ NEW, LOW-COST SPANNER WRENCH dard 1¼ " eyepieces and ac­ Disassemble Lenses, Cam­ cessory equipment; lightweight eras, etc. Completely ver­ aluminum body casting (not satile top-quality tool. Ideal cast iron); focusing tube and for repairing instruments, rack of chrome-plated brass; optics, or just plain tinker­ body finished in black wrinkle ing. Excellent design. Alu­ paint. minum hex-bodied tips slip into hex-hollowed arms and lock secure—will For Reflectors not rotate. Fully adjustable for ½" to 7" Stock # 50,077-V (less diagonal holder) $8.50 ppd. diam. retaining rings, even greater with longer Stock #60 ,049-V (diagonal holder only) 1.00 ppd. bars. Adjustable legs permit extending tips from For Refractors 1½ ” to 3" below spanner wrench body. Inch: Stock #50 ,103-V (for 2⅞ " I D. tubing) 12.95 ppd. 2 high-tensile steel hex bars 3½" lg. and 7" Stock #50 ,108-V (for 3⅞ " I.D. tubing) 13.95 ppd. (⅜” across flats), 3 pairs general purpose tips—two .025" thick flat tips, two .062" thick flat tips, and two .062" diam. pintype tips. ORTHOSCOPIC EYEPIECES Or make your own special purpose tips from Wide, flat field—better correc­ simple 7/32" Allen wrenches. tion under high magnification- Stock No. 70,751-V ...... $ 12.50 ppd. excellent eye relief. The orthoscopic eyepiece is MAIL COUPON for FREE CATALOG “V” one of the most important Completely new edition. 148 pages. and best corrected eyepieces Nearly 4000 BARGAINS. for astronomical work. These are of a four-element design, with EDMUND SCIENTIFIC CO. coated lenses, and are standard 1¼ " outer Barrington, New Jersey diameter, precision made. Please Rush Free Catalog “ V ” Stock #30,364-V . . . . 4mm.. $14.50 ppd. Name ...... Stock #30,404-V . . . . 6 mm.. 14.50 ppd. Stock #30,405-V . . . . 12.5 mm. . 14.50 ppd. Address ...... Stock #30,406-V . . . . 18mm.. 14.50 ppd. City...... Zone...... State...... Stock # 30 ,407-V . . . . 25 mm. . 14.50 ppd. ORDER BY STOCK NUMBER .SEND CHECK OR MONEY ORDER. SATISFACTION GUARANTIED! EDMUND SCIENTIFIC CO.,BARRINGTON, N.J. OPTICS OF CANADA P.O. BOX 4, POSTAL STATION C, HAMILTON, ONTARIO 4" REFLECTING TELESCOPE SEE the craters and mountain ranges on the moon, rings of Saturn, Great Nebula in Orion, the Moons of Jupiter and countless other fascinating sights with this low priced astronomical telescope.

5 X FINDER BARREL

• Attractively finished in white baked enamel on steel with chrome and black trim • 35 inches long • Diagonal mirror held firmly with adjustable spider • Fully adjustable smooth working eyepiece holder

EYEPIECES FOCAL LENGTH • Comes complete with two coated • 900 M.M. eyepieces and • 4 inch aluminized mirror Barlow • 1-20 M.M. Huygens eyepiece (gives 45 power) • 1-6 M.M. Huygens eyepiece (gives 150 power) • 1-2X Barlow (doubles eyepiece power)

MOUNT • Altazimuth mount • Black crackle finish • Smooth working tension controls

TRIPOD

• Folding hardwood tripod • 29 inches long extends to 53 inches

Shipped Free to nearest Express Office anywhere in Canada. Additional eyepiece available PRICE COMPLETE AS ABOVE ONLY ...... $59.95 FREE CATALOGUE AVAILABLE ON REQUEST Send money order or cheque with order please. Ontario residents add 3% provincial sales tax (except on books)

Prices subject to change without notice. THE TINSLEY 8-INCH CASSEGRAIN

Finest of its size, this superb optical instrument is manufac­ tured by Tinsley Laboratories, Inc.—the leading name in ob­ servatory-type telescopes of all sizes.

OPTICAL SYSTEM Designed and manufactured to the same high standards main­ tained by Tinsley Laboratories for large observatory-type in­ struments.

EQUATORIAL MOUNT • Rugged castings provide the most stable 8-inch mounting on the market today. • Polar axle mounted on 6-inch-diameter ball bear­ ings. • Input worm on sealed precision bearings. • Right ascension slow-motion remote electrically controlled by an exterior frequency- controlled unit. • Setting circles 9 inches and inches in diameter. • Adjustable declination 0—90 degrees. • Synchronous, alternat­ ing-current drive. • Adjustable locking clamps on both axes.

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nova for SCHOOL & COLLEGE n o v a I I I A new planetarium, simple in oper­ ation, low in cost yet fulfilling all instructional requirements. Motor driven annual and daily mo­ tion. Forward and reverse. Preci­ sion gear drive interlock on planets, sun and moon. Incorporates neces­ sary features as a complete teach­ ing unit for schools and colleges. 14'8" and 20' domes available. oWrite for catalog a division harmonic reed corp.

(Code 215) 825-0434 n o v a LABORATORIES UNION HILL PARK, WEST CONSHOHOCKEN, PENNA. McLau g h l in planetarium of the ROYAL ONTARIO MUSEUM / UNIVERSITY OF TORONTO The McLaughlin Planetarium will be a major planetarium of 500-seat capacity and is scheduled to open in 1967. It will require staff in the following areas, appointments to be made after July 1, 1966. Professional. With qualifications in the fields of astronomy and/or planetarium operation. Technical. With qualifications in the fields of electrical, electronic and/or machine technology. As the function of the Planetarium is the teaching of Astronomy through audio-visual presentation, prior experience in such related areas as education, stage management, radio or television would be an asset. Interested persons are invited to direct a confidential letter of inquiry to: D r. V. B. M e e n , Royal Ontario Museum 100 Queen’s Park, Toronto 5, Ontario, Canada

CALENDAR 1966 DOMELESS SOLAR REFRACTIVE TELESCOPE

The fact that no dome is used in conjunction with this solar refractive telescope eliminates almost all impairment of image quality by fringe formation in the proximity of the objective.

The Coud6 mounting permits the use of a high-dispersion spectrograph permanently fixed in the observation tower. CARL ZEISS CANADA LIMITED 14 Overlea Blvd., Toronto 17, Ont. UNITRON'S 6" Refractor on left, 4" on right

Amateur and professional astronomers alike Imagine yourself at the controls of this 6" continue to proclaim their enthusiasm and high UNITRON—searching the skies, seeing more praise for UNITRON's new 6-inch Refractor. than you have ever seen before, photo­ And little wonder—for this latest and largest graphically recording your observations—truly, UNITRON offers features, precision, and per­ the intellectual adventure of a lifetime. formance usually associated only with custom- Full specifications are given in the UNITRON built observatory telescopes of much larger Telescope Catalog available on request. Thera aperture. Here, indeed, is the ideal telescope are three massive 6" models from which to for the serious observer and for the school and choose with prices starting at $5125. college observatory. SEE OUR ADVERTISEMENTS ON THE INSIDE PAGES

INSTRUMENT COMPANY - TELESCOPE SALES DIV. 66 NEEDHAM ST., NEWTON HIGHLANDS, MASS. 02161